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Dentofacial Morphology in Obese and Non-Obese Children With and Without Obstructive Sleep Apnea
by
David Justin Simone
A thesis submitted in conformity with the requirements for the degree of Master of Science (Orthodontics)
Graduate Department of Dentistry University of Toronto
© Copyright by Dr. David Justin Simone 2016
ii
Dentofacial Morphology in Obese and Non-obese Children With and Without Obstructive Sleep
Apnea
David Simone
Master of Science (Orthodontics)
Graduate Department of Dentistry
University of Toronto
2016
Abstract
Introduction: Several craniofacial abnormalities have been suggested to contribute to
obstructive sleep apnea. These characteristics vary significantly among the literature and are
limited by the infrequent use of polysomnogprahy, the gold standard for diagnosing and
quantifying obstructive sleep apnea.
Objective: To compare the prevalence of facial and/or dental imbalances in children with and
without obstructive sleep apnea in cohorts of obese and non-obese children.
Methods: A prospective, cross-sectional study of children (ages 4-16) who were referred for a
polysomnogram at The Hospital for SickKids. Facial features and malocclusion was assessed
clinically by one dentist, blinded to the PSG results.
Results/Conclusions: Horizontal excess (overjet) was the only dentofacial finding which was
significantly more common in children with obstructive sleep apnea as compared to those
without obstructive sleep apnea (p=0.04). Dentofacial characteristics were also not different
between children using positive airway pressure therapy and children not on positive airway
pressure therapy
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Acknowledgments
I am grateful to all the people who have supported me and helped me throughout this
process. I would first like to thank my supervisors, Dr. Reshma Amin and Dr. Bryan Tompson,
without whom this project wouldn’t have been successful without your endless guidance and
advice. I would also like to thank my committee members, Dr. Fernanda Almeida, Dr. Nelly
Huynh, and Dr. Indra Narang, for your contribution to this project. You are all responsible for
guiding me in the proper direction to complete this project.
Secondly, I would like to thank the numerous people who dedicated their time that
allowed this project to be completed in a timely manner. I would like to thank Nicole Sidhu,
Nadia Kabir, Aman Sayal, and Tanvi Naik for helping with entering data into the database,
coordinating patient schedules, and preparing appropriate consents for patients. I would like to
thank Allison Zweerink for informing me of the schedules of the nightly polysomnograms and
Derek Stephens for your help with the statistical analyses.
Finally, I would like to thank my beautiful wife, Joanna and my two precious daughters,
Amalia and Violette. This project is dedicated to you. Without your infinite support and never-
ending love, I would not have been able to get through the last three years. Thank you for
picking up the slack when I was busy concentrating on school related work. Without a doubt, I
would not have been able to get through any of this without you.
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Table of Contents
Abstract ……………………………………………………………………………..... ii
Acknowledgments ……………………………………………………………………. iii
_Table of Contents …………………………………………………………………….. iv
List of Tables. ………………………………………………………………………… vi
List of Figures ………………………………………………………………………... vii
List of Abbreviations ………………………………………………………………… viii
List of Appendices …………………………………………………………………… x
Chapter 1: Background ………………………………………………………….. 1
1.1 Obstructive Sleep Apnea ………………………………………………… 1
1.2 Obesity …………………………………………………………………… 2
1.3 Epidemiology of OSA …………………………………………………… 3
1.4 Pathophysiology of OSA ………………………………………………… 3
1.5 Obesity and OSA ………………………………………………………… 10
1.6 Complications of Pediatric OSA ………………………………………… 12
1.7 Diagnosis ………………………………………………………………… 14
1.8 Pediatric Obstructive Sleep Apnea Treatment …………………………… 18
1.9 OSA and Craniofacial and Dentofacial Development …………………… 24
1.10 Rationale …………………………………………………………………. 25
1.11 Study Aim ………………………………………………………………… 26
Chapter 2: Materials and Methods ……………………………………………... 27
2.1 Subjects……………………………………………………………………... 27
2.2 Study Procedures …………………………………………………..………. 27
v
2.3 Demographics and Anthropometric Measures ……………………….……. 28
2.4 Sleep Questionnaires ………………………………………………………. 29
2.5 Clinical Orthodontic Examination ……………………………………….… 30
2.6 Polysomnogram …………………………………………………………..... 35
2.7 Statistical Analysis ……………………………………………………….... 36
2.8 Study Outcomes ……………………………………………………………. 37
2.9 Hypothesis ……………………………………………………………….… 37
Chapter 3: Results …………………………………………….............................. 38
3.1 Intra-rater Reliability ………………………………………………………. 38
3.2 Study Participants ………………………………………………………….. 39
3.3 Polysomnography Results …………………………………………………. 42
3.4 Questionnaire Results ……………………………………………………… 45
3.5 Dentofacial Morphology……………………………………………………. 49
Chapter 4: Discussion ……………………………………………........................... 55
Appendix A ……………………………………………............................................ 61
Appendix B ……………………………………………............................................ 62
Appendix C ……………………………………………............................................ 71
Appendix D ……………………………………………............................................ 72
Bibliography……………………………………………........................................... 73
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List of Tables
Table 1.1 Signs and Symptoms of Pediatric Obstructive Sleep Apnea ……………….…………………. 26
Table 2.1 Inclusion and Exclusion Criteria ……………………………………………………………… 38
Table 2.2 Summary of Study Procedures ……………………………………………............................... 39
Table 2.3 Centers for Disease Control and Prevention Weight Categories …………................................ 39
Table 2.4 Frontal View Examination …………………………………………………………………….. 41
Table 2.5 Profile View Examination …………………………………………………………………….. 42
Table 2.6 Functional Assessment ……………………………………………………............................... 43
Table 2.7 Intra-Oral Examination ………………………………………………………………………... 44
Table 3.1 Intra-rater reliability …………….………………………………………................................... 49
Table 3.2 Subject Groups ……………………………………………………………................................ 51
Table 3.3 Demographics of the Four Study Cohorts (excluding PAP group)………. …………………… 52
Table 3.4 Demographics of OSA vs. No OSA Groups (excluding PAP group) …………………………. 53
Table 3.5 PSG Results across the Four Cohorts (excluding PAP group) ……………….………………... 53
Table 3.6 PSG results of OSA vs. No OSA Groups (excluding PAP group) ……………….……………. 55
Table 3.7 Spruyt and Gozal Questionnaire results across the Four Cohorts (excluding PAP group)…….. 57
Table 3.8 Frequencies of Spruyt and Gozal Scores of OSA vs. No OSA groups (excluding PAP group).. 57
Table 3.9 Pediatric Sleep Questionnaire Results across the Four Cohorts (excluding PAP group)……… 59
Table 3.10 Frequencies of PSQ Scores of OSA vs. No OSA groups (excluding PAP group) …………….. 59
Table 3.11 Prevalence of Dentofacial Characteristics across the Four Cohorts (excluding the PAP group). 61
Table 3.12 Dentofacial Morphology of OSA vs. No OSA Groups (excluding PAP group) ………………. 62
Table 3.13 Univariate Analysis for Various Dentofacial Characteristics (excluding the PAP group)……... 63
Table 3.14 Dentofacial Morphology of Obese & OSA vs. Obese & PAP groups ……………….………… 64
Table 3.15 Multiple Regression Model for the Presence of OSA in the Study Cohort Excluding Children Using PAP Therapy……………….……………….……………….……………….…………...
65
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List of Figures
Figure 4.1 ROC Curve for Spruyt Gozal Score ……………………………………. 58
Figure 4.2 ROC Curve for PSQ Score……………………………………………… 60
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List of Abbreviations
SDB: Sleep Disordered Breathing
OSA: Obstructive Sleep Apnea
CA: Central Apnea
HS: hypoventilation syndrome
AT: Adenotonsillectomy
PSG: Polysomnogprahy
REM: Rapid Eye Movement
ICSD: International Classification of Sleep Disorders
AASM: American Academy of Sleep Medicine
BMI: Body Mass Index
CDC: Centers for Disease Control and Prevention
AHI: Apnea-Hypopnea Index
MRI: Magnetic Resonance Imaging
EMG: Electromyography
Pcrit: Critical Nasal Pressure
CRP: C-reactive protein
IL-6: Interleukin-6
GCR: Glucocorticoid receptor gene
TNF-α: Tumour necrosis factor-alpha
ICS: Intranasal Corticosteroid
OM: Oral Montelukast
ADHD: Attention-deficit/hyperactivity disorder
ANP: atrial natriuretic peptide
ADH: antidiuretic hormone
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PSQ: Pediatric Sleep Questionnaire
EEG: Electroencephalography
EOG: Electrooculography
HRQOL: Health Related Quality of Life
LDL: Low density lipoprotein
HDL: High density lipoprotein
OAI: Obstructive Apnea Index
PAP: Positive Airway Pressure
CPAP: continuous pressure airway pressure
BPAP: Bi-level positive airway pressure
RME: Rapid Maxillary Expansion
CBCT: Cone-beam computed tomography
AI: Apnea Index
SRDB: Sleep related breathing disorder
IOTN: Index of Orthodontic Treatment Need
NPAF: Nasal Pressure Airflow
SaO2 : Oxygen saturation
EtCO2: End-tidal Carbon Volume
TcCO2 : Transcutaneous carbon dioxide
OAHI: Obstructive apnea-hypopnea index
CAI: Central apnea-hypopnea index
ANOVA: Analysis of Variance
ICC: Intraclass Correlation Coefficient
OR: Odds ratio
ROC: Receiver Operating Curve
x
List of Appendices
Appendix A Spruyt and Gozal Sleep Questionnaire
Appendix B Pediatric Sleep Questionnaire (PSQ)
Appendix C Pediatric Polysomnogram Set up
Appendix D Pediatric Polysomnogram Data Recording
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Chapter 1 Background
Sleep disordered breathing (SDB) is a broad term encompassing abnormalities in
respiratory pattern, gas exchange and sleep architecture during sleep.1 SDB includes: i)
obstructive sleep apnea (OSA), episodes of complete or partial airway obstruction; ii)
central apnea (CA), prolonged pauses in the absence of respiratory effort; and iii)
hypoventilation, persistent low tidal volume breathing or bradypnea causing hypercarbia
and hypoxemia.2 OSA is the most common subtype of SDB affecting 1-5% of healthy
children.3 Adenotonsillar hypertrophy is the most common cause of OSA in healthy
children. The first-line treatment for OSA is adenotonsillectomy (AT).
1.1 Obstructive Sleep Apnea
OSA is defined by the American Thoracic Society as a “functional disturbance in
sleep characterized by transient and partial/complete obstruction of the airways which
interrupts sleep, resulting in disruption of normal gas exchange (intermittent hypoxia and
hypercapnia) and sleep fragmentation1.” OSA in children was first described
systematically in 19762 using clinical symptoms and polysomnogpraphy (PSG). Since
then the recognition of abnormal breathing during sleep has progressed tremendously in
the last two decades, with the realization that childhood OSA is both common and
serious. The understanding of the pathophysiology has improved, although much
remains to be known. There is increased recognition of the relationship between
respiratory abnormalities during sleep and adverse consequences.
Children with OSA tend to have a different pattern of breathing during sleep than
adults. Children have a higher arousal threshold than adults3. As a result, they frequently
do not arouse in response to obstructive events, and most studies have demonstrated the
preservation of sleep architecture34 or only minimal changes in sleep architecture. This is
in contrast with OSA in adulthood which is associated with significant sleep
fragmentation and decreased slow wave and rapid eye movement (REM) sleep4,55,6. In
children, OSA is characteristically more severe in REM sleep secondary to the relative
muscle atonia: a state specific deficit in upper airway function
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With this increasing recognition of SDB in children, many classification systems
have been developed. However, the International Classification of Sleep Disorders
(ICSD) is most frequently used. The ICSD was first published in 1990 by the American
Academy of Sleep Medicine (AASM) along with the Japanese Society of Sleep Research,
Latin America Sleep Society and European Sleep Research Society. It was further revised
in 2007 (Second Edition), and then again most recently in 2014 (Third Edition). OSA is
classified within the sub-group of ‘Sleep-Related Breathing Disorders6.’
1.2 Obesity
Obesity is defined as a Body Mass Index (BMI) at or above the sex-specific 95th
percentile of BMI for age, based on the 2000 Centers for Disease Control and Prevention
(CDC) Growth Charts7. There has been an increasing trend in childhood obesity
worldwide. In 1978, childhood obesity among Canadian children and adolescents aged 3-
19, was 5%. In 2013, the prevalence has increased to 13%7.
Obesity in children and adolescents is now recognized as a major medical and
public health problem that affects nearly every major organ system8. Childhood obesity
has both immediate and long-term effects on physical and mental health. Children with
obesity are more likely to have risk factors for cardiovascular disease, such as high
cholesterol or high blood pressure. In a population-based sample of 5- to 17-year-olds,
70% of children with obesity had at least one risk factor for cardiovascular disease.9 In
addition, children and adolescents with obesity are at greater risk for bone and joint
problems, sleep apnea, and social and psychological problems such as stigmatization and
poor self-esteem10. Over the long-term, children with obesity are more likely to be obese
as adults11,12 are therefore at higher risk of developing cardiovascular disease, Type 2
diabetes, stroke, several types of cancer, and osteoarthritis13.
Craniofacial morphology has also been shown to differ between obese and normal
adolescents. In 2005, Sadeghianrizi et al14 compared craniofacial morphology in obese
and normal adolescents using lateral cephalometric radiographs. They found that obese
adolescents exhibited significantly larger mandibular and maxillary dimensions than
normal adolescents. IN general, obesity was associated with bimaxillary prognathism and
relatively greater facial measurements14.
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1.3 Epidemiology of OSA
OSA is a common condition in children of all ages, from neonates to adolescents,
and can result in severe complications if left untreated. Diagnostic criteria for OSA
among adults is defined as an apnea-hypopnea index (AHI) of 5 or greater events per
hour on nocturnal PSG and evidence of disturbed sleep, daytime sleepiness, or other
daytime symptoms15. The diagnostic criteria for OSA in children is heterogeneous across
studies. At present, an AHI of 1 to 5 events per hour is most frequently used to define
OSA in children 15. From the available studies, the estimated prevalence rates of OSA in
healthy children range between 1.2% and 5.7%16-18 depending on the AHI threshold for
OSA diagnosis. If these prevalence rates were applied to the 2011 Census of Canada
population estimates, that would translate between 93,425 and 443,772 Canadian children
aged 0-19 years being diagnosed with OSA, which is equivalent to 1300-5700 children
per 100,000 children as being diagnosed with OSA.
Children between 2 and 8 years of age are at increased risk of OSA as this
coincides with the peak of adenotonsillar hypertrophy in childhood17,19. In general,
infants or older children outside this age window are likely have additional or other
underlying etiologic factors such as dentofacial abnormalities or neuromuscular disease
predisposing them to the development of OSA16,17,19,20.
In contrast to adults, where OSA is more common in men than women, OSA in
children appears to occur equally amongst the sexes20-22. OSA has been shown to have a
higher prevalence amongst African American children than Caucasian children15,23 and
Asians have more severe OSA than matched Caucasians24.
1.4 Pathophysiology of OSA
While the clinical features of OSA are well understood, the understanding of its
pathogenesis remains incomplete. OSA is a result of a balance between structural factors
and functional factors and both appear to play a role. Upper airway anatomy as well as
collapsibility is important in the pathogenesis of OSA. The patency of the upper airway is
determined by a balance between the intraluminal negative pressure of the airway and the
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soft tissue structures that support the upper airway23,25. When the collapsing forces are
great enough to obstruct the airway, an obstructive apnea or hypopnea can occur.
1.4.1 Upper Airway Anatomy
The upper airway is composed of muscle and soft tissue but lacks rigid or bony
support. Most notably, it contains a collapsible portion that extends from the hard palate
to the larynx. It has the ability to change shape and momentarily close for speech and
swallowing during wakefulness. This also renders the upper airway vulnerable to collapse
during sleep.
High-resolution magnetic resonance imaging (MRI) has been utilized to
determine the size of the upper airways structure in children26,27. As compared with
control subjects, children with OSA have a smaller oropharynx, larger adenoids, tonsils
and retropharyngeal nodes26. Arens et al.27have shown with regional analysis of MRIs
that the upper airway in children with OSA is most restricted where the adenoids and
tonsils overlap. However, with segmental analysis, the upper airway has been shown to
be restricted throughout the initial two-thirds of its length and that the narrowing is not in
a discrete region adjacent to either the adenoid or tonsils, but rather in a continuous
fashion along both27. Furthermore, Schiffman et al28 used MRI to determine the mandible
dimensions of children with OSA (24 subjects with mild to moderate OSA), and
demonstrated that a smaller mandible is not a feature in children with OSA.
The tonsils and adenoids grow progressively during childhood and usually
reach maximal size by the age of 1229. MRI has also shown that in children with habitual
snoring, enlarged tonsils and adenoids restrict the upper airway and that soft palate
volume is also larger in children with OSA30. Surgical treatment for OSA in these
children have been shown to reduce symptoms and improve, quality of life, and PSG
findings, thus providing evidence of beneficial effects of early AT31. However,
adenotonsillar hypertrophy is only one of the potential determinants of OSA in children
given that OSA persists in select patients after AT32.
In children with certain medical conditions, such as Down Syndrome, the
prevalence of OSA is much higher (30%-55%) than in otherwise healthy children33.
Craniofacial abnormalities which predispose these children to OSA include midfacial
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hypoplasia and mandibular hypoplasia, glossoptosis, an abnormally small upper airway
with superficially positioned tonsils and relative tonsillar and adenoidal hypertrophy,
hypopharyngeal collapse, tracheal stenosis, and laryngomalacia23,33.
Furthermore, cephalometric studies in children with OSA frequently report
narrower maxilla34, mandibular retrognathia35,36, longer lower facial height35-37, and
caudal placement of the hyoid bone38. A reduced upper airway sagittal width has also
been reported based on a reduced distance on lateral cephalometric radiographs as
measured from the posterior nasal spine to the adenoids. On average, this distance is
2.60-5.60mm shorter in children with OSA compared with healthy controls39 However,
other studies report no differences in measures of maxillary and mandibular width,
length, or volume between patients with OSA and normal control subjects40. Thus, the
contribution of skeletal abnormalities to the development of OSA in otherwise normal
children is controversial32.
In 2013, Flores-Mir et al, conducted a systematic review and meta-analysis to
consolidate the current knowledge of craniofacial morphological characteristics
associated with upper airway constriction resulting is OSA in children. Their study only
included cephalometric values and did not include a complete description of dentofacial
characteristics. The authors identified nine articles and found that three cephalometric
variables, the angle between the mandibular plane and sella nasion line (MP-SN), the
angle from SN to B point (SNB) and the angle from A point to nasion point to B point
(ANB), were significantly different between children with and without OSA. Children
with OSA had a steeper mandibular plane angle (MP-SN = +4.2°), a more retrusive
mandible (SNB = -1.79°), and were more likely to show a class II skeletal pattern (ANB
= +1.38°)41. Similar findings were found in the systematic review by Katyal et al39. The
authors demonstrated that children with OSA and primary snoring showed increased
weighted mean differences in the ANB angle of 1.64° and 1.54°, respectively, compared
with the controls. The increased ANB angle was primarily due to a decreased SNB angle
in children with primary snoring by 1.4°. In this meta-analysis, PSG was performed to
determine the presence and severity of OSA.
1.4.2 Upper Airway Collapsibility
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The pathophysiology of OSA in children is a complex interaction between an
airway predisposed toward collapse and neuromuscular compensation. Even though
anatomical determinants have been shown to be of critical importance to the development
of OSA, they do not completely account for the pattern of SDB32. Most children with
severe OSA are able to maintain normal sleep state distribution, particularly REM and
slow wave sleep, despite having obstructive apneic episodes4,42. This suggests that there
may be a compensation to maintain airway patency during obstructive episodes via
neuromuscular activation, ventilatory control, and arousal threshold32.
The significance of neuromuscular modulation in maintaining airway patency is
highlighted with three clinical observations: (1) apnea is observed predominantly in REM
and stage 2 sleep rather than in wakefulness or slow wave sleep4; (2) although sedated
and anesthetized children with OSA have narrower and more collapsible airways
compared with normal control children, there is considerable overlap40,43; and (3) during
sleep, most children with OSA intermittently attain a stable breathing pattern, suggesting
that reflex neuromuscular activation below the arousal threshold is possible44.
The pharyngeal dilator muscles responsible for modulating airflow through the
upper airway include the genioglossus, hyoglossus, and styloglossus. These muscles act
in unison and produce forward movement of the tongue, increase oropharyngeal airway
size and stiffness32. During wakefulness, children with OSA have an increased
genioglossus electromyography (EMG) recording levels compared with non-OSA control
children45 suggesting a reflex activation of the muscle via mucosal mechanoreceptors to
negative airway pressure. During the initial onset of sleep, this EMG activity decreases in
both OSA children and control subjects with a subsequent increase in airway resistance
and collapsibility of the airway. However, the EMG activity remains below the wakeful
baseline during stage 2 of sleep in normal children, suggesting a mechanically stable
airway. In contrast, most children with severe OSA have an increase in EMG activity
during sleep stage 2, suggesting the need for neuromuscular compensation to maintain
airway patency46.
During collapse of the upper airway, minute ventilation decreases, which induces
a compensatory increase in respiratory effort. This results in large negative luminal
pressure during inspiration. As a result, a ‘negative pressure reflex’ causes activation of
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pharyngeal dilator muscles to decrease airway collapsibility and increase minute
ventilation32. Marcus et al.47reported that children with OSA rely on arousal mechanisms
to sustain minute ventilation, which disrupts sleep homeostasis, whereas normal children
who were subjected to inspiratory resistance loading, were able to respond to the loading
with an increased inspiratory time and sustain loads without arousing for several minutes.
That is, normal children were able to perform the negative pressure reflex without
arousal, whereas, the negative pressures reflex is diminished or completely lost in
patients with OSA32.
In adults, the critical nasal pressure (Pcrit) at which the upper airway collapses is
higher in patients with OSA than in those with primary snoring. In 1994, Marcus et al48
compared the Pcrit between prepubertal children with OSA and those with primary
snoring. Pcrit was determined by correlating the maximal inspiratory airflow with the
level of positive or negative nasal pressure applied via a nasal mask. As in adults, they
found that the maximal inspiratory airflow varied in proportion to the upstream (nasal)
rather than the downstream (esophageal) pressure changes. Pcrit was 1 ±3 cmH2O in
OSA compared with -20 ± 9 cmH2O in primary snorers. They concluded that Pcrit, a
measure of airway collapsibility, correlated with the degree of upper airway obstruction
and was reduced postoperatively, consistent with increased upper airway stability.
The negative pressure reflex is important in maintaining upper airway patency by
exciting pharyngeal muscle dilators through neuromuscular compensation. It is plausible
that mucosal inflammation or edema could impair the afferent limb of this reflex. It is
hypothesized that snoring induces a mucosal inflammatory response resulting in swelling,
affecting upper airway resistance and/or collapsibility32. .
1.4.3 Inflammation
It has been previously established that OSA induces a systemic proinflammatory
response which can result in end-organ dysfunction49. Sleep apnea in children is
associated with increased inflammatory responses and increased plasma levels of C-
reactive protein(CRP) and interleukin-6 (IL-6)50. In 2014, Mutlu et al51 investigated the
clinical significance of preoperative serum CRP, interleukin-6 (IL-6), fetuin-A, cystatin
C, adiponectin and tumor necrosis factor-alpha (TNF-α) levels in children with
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adenotonsillar hypertrophy and compared the results with post surgical values. They
found that levels of cytokines in children with SDB secondary to adenotonsillar
hypertrophy decreased after surgical treatment. They concluded that the risks of
development of cardiovascular disease are decreased in association with lower levels of
cytokines. 51.
Goldbart et al.52 have demonstrated the presence of upper airway inflammation in
children with OSA. They found increased expression of leukotriene receptors in tonsillar
tissue from children with OSA compared with children with recurrent throat infections.
In a subsequent study, Goldbart et al53 found an upregulation of the glucocorticoid
receptor gene (GCR) expression in OSA derived adenoid and tonsil tissues compared
with tissue from children with recurrent throat infections. Translational studies
incorporating intranasal corticosteroids54, leukotriene receptor antagonists55, or both56,
for the treatment of pediatric OSA have demonstrated a reduction in OSA severity. The
largest study to date looking at the anti-inflammatory therapy for mild OSA was
published in 2014 by Kheirandish-Gozal et al57. A combination of intranasal
corticosteroid (ICS) and oral montelukast (OM) for 12 weeks normalized PSG sleep
findings in 62% of their 752 sample size diagnosed with mild OSA. Thus, a combination
of ICS and OM as treatment of mild OSA appears to be effective and have lasting
effects57.
Tauman et al.58 first correlated the increase in CRP levels among American
children with OSA with AHI, arterial oxygen saturation, and arousal index measures.
Although CRP is a nonspecific marker of inflammation, recent epidemiologic studies
suggested that CRP may participate directly in atheromatous lesion formation through
reduction of nitric oxide synthesis and induction of the expression of particular adhesion
molecules in endothelial cells59. It was noted that these increases were prominent among
children who presented with neurobehavioral complaints. They suggested that
intermittent hypoxia and sleep fragmentation of OSA may underlie these systemic
inflammatory responses. However, a subsequent group from Greece found conflicting
results that CRP levels are not significantly different between control subjects and
children with OSA60.
Since the association of plasma CRP concentrations with OSA in childhood has
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been inferred from several studies demonstrating increased circulating levels of CRP with
increasing severity of OSA, Bhattacharjee et al61 used CRP to assess if residual disease
persists post AT in children with OSA. They found that pre-AT AHI and post-AT CRP
levels were most significantly associated with residual OSA61.
OSA has also been associated with insulin resistance, hyperglycemia and
dyslipidemia in children62. Koren et al63 found that AT improved insulin sensitivity and
HDL levels, but not fasting glucose or other lipoprotein levels despite a parallel increase
in BMI z scores. This suggests that OSA is causally involved in creating an adverse
metabolic state independent from obesity because the metabolic changes did not differ
significantly between children without obesity and children with obesity or between boys
and girls. Fasting insulin was most strongly associated with post-AT AHI, such that more
children with insulin resistance were more likely to have residual OSA.
Koren et al64 followed up this study to assess the independent contributions of
OSA to insulin resistance and dyslipidemia in large pediatric cohort(n=459). They found
that although obesity was the primary driver of most associations between OSA and
metabolic measures, sleep duration was inversely associated with glucose levels, with
stage 3 Non REM sleep (N3) and REM sleep being negatively associated and sleep
fragmentation positively associated with insulin resistance measures. In children with
mild OSA, the presence of obesity increased the odds for insulin resistance, while higher
AHI values emerged among obese children who were more insulin-resistant64. Thus the
exclusive presence of interactions between OSA and obesity in the degree of insulin
resistance is coupled with synergistic contributions by sleep fragmentation to insulin
resistance in the context of obesity. Insufficient N3 or REM sleep may also contribute to
higher glycemic levels independent of obesity64.
It is difficult to distinguish between inflammatory mechanisms leading to SDB as
opposed to the systemic/local inflammation resulting from the presence of SDB.
However, most data support the concept of a disease that is associated with inflammation
that is ameliorated after surgery at the systemic and the local airway level. In contrast,
there are no data that confirm pre-existing inflammation in children with newly
diagnosed OSA65.
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1.5 Obesity and OSA
Since its initial description in 1976, obesity and OSA has become widely
recognized as a highly prevalent condition in children2. The last two decades has
witnessed a shift from the classic presentation of children with OSA (i.e. adenotonsillar
hypertrophy and failure to thrive) to a majority of children being overweight or obese,
even though adenotonsillar hypertrophy continues to play a role in the latter group66.
Early descriptions of childhood OSA rarely described obese patients. Most
children were of normal weight and failure to thrive was a common complication67.
However, with the epidemic of childhood obesity continually rising, the epidemiology of
childhood OSA is shifting towards obesity as being an important risk factor. The risk of
OSA is greatly increased by obesity in children, with an estimated prevalence ranging
from 19 to 61% depending on the definition of OSA, the degree of obesity and the age of
the study population68.
Compared to the estimated 3% prevalence of OSA in 2- to 8-year-old children15,
the risk of OSA in obese children has been estimated to be as high as 36%69, and may
exceed 60%70 when habitual snoring is present. The presence of both OSA and obesity
sets into motion a viscous cycle, where the presence of OSA affects metabolic
requirements which can perpetuate the tendency towards obesity71,72. In addition,
sleepiness will reduce the likelihood of engaging in physical activity and enhance eating
behaviors that favor calorie-dense foods66,72.Clinic-based and epidemiological studies
have confirmed that obesity is an important risk factor for OSA73 and is one of the
strongest predictors of SDB in both adults and children74. In a case-control study design,
Redline et al75 examined risk factors for SDB in children aged 2-18 years (n = 399), and
found that the risk among obese children was increased four to five fold.
The proposed physiologic mechanisms that may contribute to OSA in obese
children include anatomic and functional factors restricting the upper airway, alterations
in chest wall mechanics affecting lung volumes and upper airway collapsibility, and
inflammatory and metabolic factors that may perpetuate the disorder66,76.
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Adenotonsillar hypertrophy has been recognized as an important anatomic cause
of restriction of the upper airway and contributing to the development of OSA in children
with obesity77-81 However, residual OSA after AT has been reported in 54-76% of these
children82 compared with approximately 15-20% in children without obesity80,83.
Nandalike et al84 were the first to quantify the volumetric changes in the upper airway in
children with obesity and OSA after AT. They found that AT increased the volume of the
nasopharynx and oropharynx, reduced tonsils, but had no effect on the adenoid, lingual
tonsil, or retropharyngeal nodes. They also noted a small significant increase in the
volume of the soft palate. These findings could explain the lower success rate of AT
reported in children with obesity and OSA.
With regards to obesity, the pathophysiologic mechanisms for OSA are both
mechanical and functional. Mechanically, deposition of adipose tissue within the base of
the tongue and the pharynx results in decreased airway size and increase airway
resistance85. Functionally, there is a reduced lung volume due to displacement of the
diaphragm by the obese abdomen and a decreased central ventilatory drive78. Using MRI,
Arens et al77 determined the anatomic risks factors associated with OSA in obese children
as compared with obese control subjects without OSA. As compared with control
subjects, subjects with OSA had a smaller oropharynx (P= 0.05) and larger adenoid (P =
0.01), tonsils (P = 0.05), and retropharyngeal nodes (P = 0.05). The size of lymphoid
tissues correlated with severity of OSA whereas BMI did not have a modifier effect on
these tissues. Subjects with OSA demonstrated increased size of parapharyngeal fat pads
(P= 0.05) and abdominal visceral fat (P =0.05). The size of these tissues did not correlate
with severity of OSA and BMI did not have a modifier effect on these tissues. In
conclusion, upper airway lymphoid hypertrophy is significant in obese children with
OSA. The lack of correlation of lymphoid tissue size with obesity suggests that this
hypertrophy is caused by other mechanisms. Although the parapharyngeal fat pads and
abdominal visceral fat are larger in obese children with OSA they could not find a direct
association with severity of OSA or with obesity77.
Recent evidence suggests that OSA is associated with a state of chronic
inflammation characterized by increased oxidative stress, pro-inflammatory cytokine
production, and metabolic deregulation86. It has been shown to also contribute to the
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pathogenesis and progression of nonalcoholic fatty liver disease, via the deleterious
effects of chronic intermittent hypoxia on liver metabolism and inflammation87. Alkhouri
et al86 demonstrated that circulating markers of hepatocyte apoptosis were significantly
altered in children with OSA. More specifically, levels of soluble CD163, a marker of
macrophage activation, increased significantly in children with OSA and improved after
OSA treatment. These findings indicate that children with OSA have increased apoptotic
and inflammatory pressures86.
1.6 Complications of Pediatric OSA
It is now well established that SDB may lead to serious and measurable end-organ
dysfunction. This is especially important in children because of the risk of life-long
negative sequelae. The effects of untreated SDB include neurocognitive deficits,
cardiovascular complications, inflammation, growth impairment, reduction in health
related quality of life (HRQOL) and increased healthcare resource utilization.
1.6.1 Neurocognitive Complications
One of the most well-established long term sequelae of pediatric OSA is
behavioral and neurocognitive dysfunction1. Behavioral dysregulation is the most
commonly encountered comorbidity of OSA1. Sixty-one articles including over 29 000
children have directly explored the relationship between OSA and behavioral and
neurocognitive function88. The vast majority of studies consistently report some
association between OSA and hyperactivity, attention deficits and impulsivity1. Poor
school performance, impaired executive functioning, and an inverse relationships
between memory and learning have all been reported in children with OSA1.To
investigate a causal relationship between decrements in cognition and OSA, in the past
decade 19 studies have assessed neurocognition pre and post treatment for OSA1. The
majority of the studies have demonstrated significant improvements post treatment with
three studies demonstrating sustained improvements at more than a year post treatment88.
1.6.2. Cardiovascular Complications
The cardiovascular complications of SDB are of immediate importance because
earlier diagnosis and treatment can reverse these processes and prevent its consequences
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in adult life1. Recurrent episodes of upper airway obstruction, which are characteristic of
OSA result in intermittent hypoxia, intrathoracic pressure swings and sleep
fragmentation. This results in autonomic system activation supported by the followings
findings: increased urinary cathecholamines, decreased pulse transit time and alterations
in blood pressure regulation in OSA1. Right ventricular dysfunction has also been
demonstrated1.Cardiac benefits of treatment for SDB have been shown. Plasma levels of
B-type natriuretic peptide, a marker of ventricular strain, has been found to be elevated in
children with SDB and to decrease after AT1. Similarly, there is evidence of
echocardiographic improvement of elevated pulmonary pressure also after AT1.
1.6.3 Inflammatory Complications
OSA also appears to cause low grade systemic inflammation and local
inflammation. This is thought to be the result of the intermittent hypoxia and sleep
fragmentation leading to the production of free radicals and systemic oxidative stress.
Increased circulating levels of CRP, as well as adhesion molecules have also been shown.
Anti-inflammatory therapy targeting upper airway inflammation has been shown to
improve residual OSA post AT1.
1.6.4 Somatic Growth Failure
OSA can also impair somatic growth. Failure to thrive has been reported in up to
50% of children presenting for AT89. The suggested etiologies include decreased caloric
intake, increased work of breathing as well as a reduction in growth factors such as
insulin like growth factor-1 and growth hormone. Selimoglu has demonstrated significant
increases in insulin like growth factor-1 six months after adenotonsillectomy90.
Furthermore, elevations in low density lipoprotein (LDL) cholesterol along with
reduced levels in high density lipoprotein (HDL) cholesterol were observed in both obese
and non-obese children with OSA, with significant improvements after OSA
treatment91,92.
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1.6.5 Quality of Life and Healthcare Resource Utilization
Childhood SDB leads to significant decreases in HRQOL and these scores
significantly improve following treatment93.Healthcare resource utilization is a powerful
index of disease morbidity in children1. Healthcare resource utilization is significantly
increased and usage is elevated several years before an OSA diagnosis94. The total
number of admissions in children with OSA is 40% higher as compared to matched
controls.
In summary, SDB is associated with serious and measurable end-organ
dysfunction. Treatments for SDB are available and the benefits of treatment have been
demonstrated which argues for timely diagnosis and treatment of SDB to avoid long-term
negative sequelae.
1.7 Diagnosis
The management goals for childhood OSA are to 1) identify children who are at
risk for OSA; 2) diagnose children with OSA; and 3) treat children with OSA to prevent
negative sequelae of untreated disease. Diagnostic tools that have been studied include
clinical history and physical examination, patient questionnaires, and PSGs. Given the
resource intensive nature of PSGs in combination with the limited access to PSGs, the
pediatric sleep medicine field has tried to identify tools that can be used clinically to
screen for OSA.
1.7.1 Signs and Symptoms
The most common signs and symptoms, based on history and physical
examination of the child, associated with childhood OSA are summarized in Table 1.1.
Several studies have evaluated the use of history alone as a screening tool for the
diagnosis of OSA. Preutthipan et al95 aimed to determine whether parents’ observations
(such as observed cyanosis, snoring extremely loudly, shaking the child, being afraid of
apnea) could predict the severity of OSA. Although they found that some parent’s
observations are more frequently reported in children with OSA, neither any single nor
combination of observations accurately predicted the severity of OSA. They found an
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overall poor sensitivity and specificity when evaluating various historical factors in
children with OSA.
Snoring is the most common clinical symptom of OSA. It is a sensitive, non-
specific, screening symptom for OSA29. If a history of nightly snoring is elicited, a more
detailed history regarding labored breathing during sleep, observed apnea, restless sleep,
diaphoresis, enuresis, cyanosis, excessive daytime sleepiness, and behavior or learning
problems (including attention-deficit/hyperactivity disorder (ADHD)) should be
obtained96.
In children with OSA, findings on physical examination during wakefulness are
most often normal. However, there may be non-specific findings related to adenotonsillar
hypertrophy, such as mouth breathing, nasal obstruction during wakefulness, adenoidal
faces, and hyponasal speech96.
Table 1.1 Signs and Symptoms of Pediatric OSA97
Daytime Symptoms Physical Examination
• Morning headaches • Daytime sleepiness • Diagnosis of ADHD • Learning problems • Irritability • Hyperactivity
• Underweight or overweight • Tonsillar hypertrophy • Adenoidal faces • Micrognathia/retrognathia • High-arched palate • Signs of cor pulmonale • Hypertension
Nocturnal Symptoms
• Snoring • Witnessed apneas • Gasping • Paradoxical Breathing • Neck hyperextension • Nocturnal Diaphoresis • Nocturnal enuresis
ADHD is a behavioral abnormality commonly seen in children and adolescents.
Its main symptoms include inattention, hyperactivity, and impulsivity98. Attention deficit
and hyperactivity are known possible symptoms or correlates of OSA99. Chervin100 and
O’Brien18 reported that children with mild symptoms of ADHD showed a high
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prevalence of snoring and sleep problems. However, these associations may be missed in
children, because ADHD is a common primary diagnosis in itself. In conclusion, OSA
can mimic the signs of ADHD. Furthermore, unlike in adults, children with OSA,
especially younger children, rarely have excessive daytime sleepiness, and parental
reports of sleepiness vary with the questionnaire used99. If misdiagnosed as ADHD,
children may be subject to long-term methylphenidate, a commonly used medication for
ADHD, whereas recognition and treatment of the underlying sleep disorder should be
treated, to prevent unnecessary medication use.101.
A higher prevalence of nocturnal enuresis has been reported in children with
OSA. Although, the exact etiology is not yet known, it has been postulated that increased
enuresis may be because of the dampening effects of OSA on the arousal response,
changes in bladder pressure or possibly the secretion of hormones involved in fluid
regulation, such as atrial natriuretic peptide (ANP) and antidiuretic hormone (ADH) 102,103.
Nonetheless, in the majority of children with OSA, the physical examination is
normal. In addition, the presence of adenotonsillar hypertophy has not been shown to
reliably predict OSA104,105.
1.7.2 Questionnaires
Questionnaires have been developed as screening tools for the diagnosis of OSA.
At present, two of the more commonly used questionnaires to screen for SDB are the
Pediatric Sleep Questionnaire (PSQ)106 and the Spruyt and Gozal 6-item Sleep
Questionnaire107.
The PSQ (see Appendix B) was first published and validated in 2000 by Chervin
et al106. It consists of 22 item parent-reported questionnaire. It is composed of four
subscales for SDB, snoring, sleepiness, and behaviour. The PSQ performed slightly better
than other published questionnaires as a screening tool for the detection of OSA with a
sensitivity of 0.85 and a specificity of 0.87 when using an established cut-off score of
0.33 for the original validation study29. In a follow up study, using PSG to diagnose OSA,
Chervin et al108 subsequently found a lower sensitivity, 0.78 and specificity 0.72.
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In 2012, Spruyt and Gozal107 (see Appendix A) developed a set of six
hierarchically arranged questions that aided in the screening of children at high risk for
SDB. A total of 1,133 children between the ages of 5- to 9-years-old were evaluated
using the questionnaire. All sleep-related questions used the Likert-type responses
“never” (0), “rarely” (once per week; 1), “occasionally” (twice per week; 2), “frequently”
(three to four times per week; 3) and “almost always” (>4 times per week; 4) for the
preceding 6-month time frame. Overall, the questionnaire had a sensitivity of 59.03%,
specificity of 82.85%, positive predictive value of 35.4 and negative predictive value of
92.7.
A 2002 systematic review by Schechter et al.109, looked at the use of
questionnaires as screening tools for OSA. The authors concluded that questionnaires had
an unacceptably low sensitivity and specificity for predicting OSA. This was further
confirmed in a more recent systematic review in 2014 by De Luca Canto et al110. These
authors concluded that the PSQ had sufficiently high sensitivity and specificity to be used
as a screening tool for OSA but not as a true diagnostic tool for pediatric OSA.
1.7.3 Polysomnography
The gold standard test to diagnose OSA is an overnight PSG, also known as a
level I study111. The overnight PSG is attended by a sleep technologist during which at
least seven physiological channels are measured. An overnight PSG monitors
electroencephalography (EEG), chin and leg electromyography (EMG),
electrooculography (EOG) and cardiorespiratory variables, including respiratory effort,
heart rate, oximetry and carbon dioxide levels for approximately 8 to 10 hours. The PSG
determines the AHI which describes the severity of OSA. AHI is defined as the number
of apneas and hypopneas per hour of total sleep time. Apnea is defined as a drop in the
peak airflow > 90% of baseline, with the drop lasting at least the duration of two breaths
during baseline breathing and is associated with the presence of respiratory effort
throughout the entire period of absent airflow. Hypopnea is defined as a drop in the peak
airflow > 30% of baseline, for the duration of at least two breaths in associations with
either > 3% oxygen desaturation or an arousal112. An AHI greater than 1.5 events per
hour is a positive diagnosis for OSA113-115.
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Though PSGs are the gold standard test for the diagnosis of pediatric OSA, there
are many challenges related to performing a PSG. These include: inconvenience to the
patient and, the relative scarcity of sleep laboratories with a resulting extended wait
period between referral and actual testing. In 2014, Katz et al116 aimed to describe
pediatric sleep physician and diagnostic testing resources for SDB in Canadian children.
They found marked disparities across the province/territories with many provinces having
no practitioners or access to PSGs. In the provinces that had access to PSGs, reported
wait times ranged from <1 month to 1.5-2 years. This study clearly demonstrated a lack
of resources and services for pediatric SDB across Canada, with pronounced disparities.
Even if only affected children were tested with PSG, the authors estimate there are 7.5
times more children with OSA than the current testing capacity in Canada116.
1.8 Pediatric Obstructive Sleep Apnea Treatment
Treatment for OSA must be individualized based on the clinical assessment,
anatomy of the upper airway and severity of the disease.
1.8.1 Adenotonsillectomy
The most common cause of childhood OSA is adenotonsillar hypertrophy117. The
first line treatment for OSA in these children is AT.
Early studies showed that pre-pubertal adolescents initially considered to have
been cured of OSA by AT subsequently had recurrence as teenagers. Guilleminault et al.
showed that subjects initially treated with AT had narrowing behind the base of the
tongue and oral-facial anatomical abnormalities that either did not exist initially or had
not been identified previously118..Tasker et found that a narrow upper airway and snoring
persisted 12 years after AT119. In another study Guilleminault et al. (n =207)
demonstrated that complete resolution of OSA following AT was present in only 51% in
non-obese pre-pubertal children that were studied with PSG 3 months post-operatively120.
More recently, in a large, multicenter retrospective study, Bhattacharjee et al. (n=500)
found that although AT led to significant improvements in indices of SDB in children,
residual disease was present in a large proportion of children (70%), particularly among
older (>7 yr) or obese children121. .
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Marcus et al31 were the first to perform a randomized controlled study evaluating
the benefits and risks of AT, as compared with watchful waiting, for the management of
OSA. This Childhood Adenotonsillectomy Trail (CHAT) was designed to evaluate the
efficacy of early AT versus watchful waiting. A total of 464 obese and non-obese
otherwise healthy children between the ages of 5 to 9 years old age were included.
Children with an AHI score of more than 30 events per hour, an obstructive apnea index
(OAI) score of more than 20 events per hour, or arterial oxyhemoglobin saturation of less
than 90% for 2% or more of the total sleep time were not eligible, owing to the severity
of the PSG findings. The primary study outcome was the change in the attention and
executive-function score on the Developmental Neuropsychological Assessment
(NEPSY; scores range from 50 to 150, with 100 representing the population mean and
higher scores indicating better functioning)122. This test has well-established
psychometric properties122 and comprised three tasks (tower building, visual attention,
and auditory attention) performed under the supervision of a psychometrist. Secondary
outcomes for this study were caregiver and teacher ratings of behaviour, symptoms of
OSA, sleepiness, global quality of life, disease-specific quality of life, generalized
intellectual functions, and PSG indexes. They found that compared with a strategy of
watchful waiting, surgical treatment for obstructive sleep apnea in school-age children
did not significantly improve attention or executive function as measured by
neuropsychological testing but did reduce symptoms and improve secondary outcomes of
behavior, quality of life, and PSG findings, thus providing evidence of beneficial effects
of early AT31.
Substantial subgroup differences with regard to the normalization of PSG
findings post AT in Marcus’ et al31 randomized trial of AT were observed within each
study group. Regardless of the assigned treatment (surgery or watchful waiting),
normalization of PSG findings was seen less frequently in black children than in children
of other races, in children with obesity than in children without obesity, and in children
with a baseline AHI score above the median than in those with a baseline AHI score at or
below the median31. Among obese children, those randomly assigned to early AT had
greater reductions in symptoms and greater improvement in behavioral and PSG
outcomes than did those in the watchful waiting group31. However, there persistence of
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OSA post AT was higher in the children with obesity as compared with the children
without obesity (33% vs. 15%)31.
Overall, the results of published data on the success of AT ranges from 24 to 100
percent in the literature123. In 2009, Friedman et al.123 performed an updated systematic
review of AT for the treatment of pediatric OSA. The meta-analysis included 1079
subjects with a mean age of 6.5 years of age. The effect measure was the percentage of
pediatric patients with OSA who were successfully treated with AT based on
preoperative and postoperative PSG data. When “cure” was defined as an AHI of <1, AT
was successful only 66.3% of the time. However, although complete resolution is not
achieved in most cases, it still offers significant improvements in AHI, making it a
valuable first-line treatment for pediatric patients.
Adenotonsillectomy yields improvements in children with OSA however
complete normalization occurs in only 25% of the patients, with obesity and AHI at
diagnosis being the major determinate for the success for surgical outcome81. Therefore,
obesity should be considered as an important, potential, contributor to residual airway
obstruction after surgery with its own, independent, contribution to the pathophysiology
of OSA124.
1.8.2 Positive Airway Pressure
Positive Airway Pressure (PAP) therapy is recommended for children with
moderate to severe OSA post AT or if a child is not a candidate for AT.
PAP therapy for OSA was first developed more than three decades ago125. PAP
works by counteracting the sleep-induced negative transmural pressure that promotes
collapse and narrowing of the collapsible upper airway. PAP therapy maintains upper
airway patency via the delivery of pressurized air through an interface that is worn over
the nose or the nose and mouth. This creates a “pneumatic splint” which prevents partial
or complete collapse of the upper airway during sleep125. The aim of PAP therapy is to
normalize the obstructive AHI, improve sleep quality and normalize gas exchange. There
are two types of PAP therapy that are delivered by a mask: 1) continuous pressure airway
pressure (CPAP) and 2) Bi-level positive airway pressure (BPAP) therapy. For both
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CPAP and BPAP, the non-invasive interfaces include nasal pillows, nasal, oronasal and
full face options.
Although PAP therapy has been increasingly prescribed in children over the past
few decades due to advances in both the technology itself as well as the number of
interfaces that are available for children, the greatest barrier to PAP therapy is adherence.
In a recent study, DiFeo et al. prospectively studied children and adolescents and
concluded that PAP adherence is primarily related to family and demographic factors
rather than the severity of apnea or measures of psychosocial functioning126. This is an
additional challenge as the entire family often needs to be engaged for the child to be
adherent with PAP. Access to pediatric PSG is currently limited by a 12 -month waiting
period for PSG at Sick Kids alone, with similar wait times across Canada.
At present, the literature is insufficient and contradictory in describing the long
term effects of PAP therapy, on the development of the face, jaw, and teeth88. A few case
reports have suggested that early childhood long-term treatment using either CPAP or
BPAP carries a high risk of facial growth impairment, in particular, midface hypoplasia
and Class III malocclusions127,128. However, more recently, a small sample size, cross-
sectional study failed to show any statistically significant difference between long-term
PAP use and dentofacial abnormalities in children with persistent OSA129. This is an area
of needed further study.
1.8.3 Orthodontic Treatment
Persistent OSA post AT has also led to the consideration of orthodontic
modalities to treat OSA. There are several craniofacial abnormalities where imbalanced
development may contribute to OSA such as posterior crossbite, Class II skeletal and
dental patterns, and anterior open bite. Aside from aesthetic and occlusion benefits,
orthodontic treatment can help guide facial growth in order to correct facial imbalances,
improve swallowing, reposition tongue posture and re-establish nasal breathing130.
Early detection and treatment of children with OSA and facial imbalances may
prevent the sequelae of this disease. Early orthodontic treatment could prevent a need for
AT and provides another treatment option for children with OSA that are not adherent to
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PAP therapy.
1.8.3.1 Rapid Maxillary Expansion
Rapid Maxillary Expansion (RME) is a common orthodontic procedure used to
correct maxillary arch constriction by opening the mid-palatal suture. It is a common
treatment modality to correct posterior crossbites in the primary, mixed, or permanent
dentition.
The precise role of maxillary constriction in the pathophysiology of OSA is
unclear. However, it is known that a significant number of children with OSA have nasal
obstruction (nasal septal deviation with or without turbinate hypertrophy) associated with
a narrow maxilla. Maxillary constriction is thought to increase nasal resistance and alter
tongue position, leading to narrowing of the retroglossal airway and subsequently the
development of OSA131.
There is no evidence to support that RME enlarges oropharyngeal airway volume.
Zhao et al132 retrospectively studied 24 adolescent patients (mean ±SD age 12.8 + 1.88
years) with maxillary constriction using hyrax palatal expanders and compared that to 24
control patients (mean ±SD age 12.8 + 1.85) undergoing routine orthodontic treatment
without palatal expansion. They used cone-beam computed tomography (CBCT) to
assess changes in the volume, length, and minimum cross-sectional area of the
oropharynx. They found no statistically significant differences between the groups.
On the other hand, RME has been shown to increase nasal width and nasal cavity
dimensions. Pirelli at el.133 investigated the effect of RME on 31 children (19 boys, 12
girls) with maxillary constriction, without adenoid hypertrophy, with OSA demonstrated
by PSG. RME was performed for 10 to 20 days with 6 to 12 months of retention. The
mean AHI fell from 12.2 events per hour to less than one event per hour, demonstrating a
resolution of the SDB.
In a further study, Pirelli et al.134 evaluated if RME in 42 children with a case
history of oral breathing, snoring, and night time apneas could improve the patency of
nasal breathing and OSA. Selection criteria included no adenotonsillar hypertrophy,
BMI<24, and narrow maxillary arch determined by posterior-anterior cephalometric
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evaluation. Investigations were carried out before orthodontic treatment, one month after
treatment (T1) and after the end of orthodontic treatment (T2). All results were analyzed
by postero-anterior cephalometric evaluation in T0, T1, and T2. The results reported that
in all 42 patients, RPE therapy widens the nasal fossa and releases the septum restoring
normal nasal airflow with a disappearance of obstructive sleep disordered breathing134.
1.8.3.2 Functional Appliance Therapy
Functional appliances are removable or fixed intraoral devices which alter the
muscles forces against the teeth and craniofacial skeleton. They depend on altered
neuromuscular action to effect bony growth and occlusal development. They have been
used in children with OSA because functional appliances posture the mandible forward
and potentially enlarge the upper airway and increase the upper airspaces, improving the
respiratory function135.
In 2007, a Cochrane based review assessed the effectiveness of using functional
orthopaedic appliances for the treatment of OSA in children136. Out of 384 potentially
relevant studies, only 1 paper was included 137, demonstrating the lack of
methodologically sound research in this area. For example, there was an important
methodological problem with many papers not showing important information necessary
to assess their quality. Papers did not present information such as: how participants were
allocated to interventions, who generated the allocation, how sample size was determined
etc136.
Villa et al137, compared active oral appliance vs. no treatment and studied 32
children, with total apnea index (AI) of more than 1 event/hr diagnosed by PSG. A
decrease of at least 50% in the total AHI was considered treatment success. In 9/14
treated subjects, the AHI fell 50%. Although this study showed some results that favored
the intervention, the results must be considered with caution due to methodological
problems such as non-randomized generation of allocation, no allocation concealment, no
blinding, no sample size calculation reported, number of patients randomized different
from patients analyzed, high number of loss to follow up and no intention-to-treat
analysis was performed.
In conclusion, the available information is not enough to answer whether oral
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appliances or functional appliances are effective in the treatment of sleep apnea in
children136.
1.9 OSA and Craniofacial and Dentofacial Development
Facial growth and development is primarily dictated by genetic factors, but
environmental inputs also contribute, in particular, with respect to the mode of breathing.
Children who suffer from respiratory problems and OSA commonly exhibit disturbances
in dentofacial morphology. The growth of the dentofacial regions follows the functional
matrix theory; that is, growth occurs in response to functional needs and possibly in
response to the growth of the nasal cartilage138.
Linder-Aronson139 proposed the cause-and-effect pathway of reduced nasal
breathing during wakefulness and resultant craniofacial abnormality. When nasal
breathing is reduced, possibly from enlarged adenoids or an anatomical defect (i.e.
decreased nasal width or nasal septal deviation), mouth breathing is inevitable as the
primary mode of respiration.
Mouth breathing leads to an altered pattern of muscle recruitment in the oral and
nasal capsule, which ultimately results in skeletal changes 140.The important role of
abnormal nasal resistance during the early developmental period was demonstrated from
studies on infant rhesus monkeys140.A small silicone head was placed within the nostrils
of infant rhesus monkeys in order to induce nasal resistance for the first 6 months of
life140,141. The blockage of the nasal passage led to narrowing of the dental arches,
decrease in maxillary length, anterior cross bite, maxillary overjet and an increase in
anterior facial height140. These changes were shown to be reversible if the experimental
nasal resistance was withdrawn while the infant monkey was still in its developmental
phase.
In children, mouth breathing is most commonly associated with: an extended
posture of the head (3 to 5 degree extended craniocervical posture); retrognathic
mandible; a larger anterior facial height; a steeper mandibular plane; a lowered position
of the hyoid bone; an antero-inferior posture of the tongue compared to normal children
and a high palatal vault142. This pattern of findings has been termed “long face
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syndrome,” and is similar to the reported cephalometric findings in children with OSA35-
37. Comparable changes in the craniofacial structure have been described in a group of
subjects with large tonsils, which has been termed the “adenoidal face”139. The adenoid
face is characterized by an incompetent lip seal, a narrow upper dental arch, retroclined
mandibular incisors, increased anterior face height, a steep mandibular plane angle, and
retrognathic mandible compared with faces of healthy controls139. Thus, not only does
upper airway obstruction predispose to OSA, but it also has an adverse effect on
craniofacial development, posing an increased future risk of OSA32.
The literature reports mixed results with regards to the resolution versus the
persistence of craniofacial abnormalities after treatment for OSA. On the one hand, some
studies have shown that cephalometric variables normalize after treatment of OSA in
children. In a five year follow up study after AT in children with OSA, resolution of
maxillary and mandibular inclination abnormalities and lower face height was
observed37. On the other hand, it has been shown that open bites and cross-bites are
observed 2 years after AT in most patients143. As a general rule, if treatment is initiated at
a young enough age (before 6 years of age), the long-term dentoalveolar development is
more likely to normalize143. Dentofacial anomalies can also present as malocclusions that
can be observed during intra-oral examination. Posterior crossbite, Class II skeletal and
dental patterns, and anterior open bite have been found to be more prevalent in OSA
children versus healthy controls143. The remainder of the reported occlusal characteristics
varies significantly among the literature in children with OSA, emphasizing the need for
further research on this topic. The specific reported prevalence’s of posterior crossbite in
children with OSA ranges between 16.7% - 68.2%39,144 versus reported controls 2.4%-
23.2%39,145. The prevalence of Class II skeletal and dental patterns in OSA children
ranges in the literature between 29.3%-88%144,145 versus controls 4.9%-28%145,146. Lately,
the reported prevalence of anterior open bite in OSA children ranges between 5%-
20%67,144 and 0% in the control groups145.
1.10 Rationale
A formal dental evaluation is not standard of care for either children referred to sleep
clinics for query obstructive sleep apnea or those prescribed PAP therapy for the
treatment of OSA. Sleep physicians perform a cursory craniofacial examination including
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a basic assessment of maxillary constriction and mandibular hypoplasia. Given the
emerging evidence in the literature demonstrating an improvement in OSA with
orthodontic treatment, as well as the limited literature suggesting midfacial hypoplasia
and class III malocclusions as a result of ongoing PAP therapy, a needed first step is to
understand the prevalence of malocclusion and dental anomalies in children referred to a
sleep center for query OSA. It is also important to understand how this prevalence differs
in children that are currently being treated for OSA with PAP therapy. Determining the
prevalence of dental abnormalities and malocclusion in these cohorts of children will
inform future interventional studies to look at the relative efficacies of different treatment
interventions.
1.11 Study Aim
The aim of our study is to report on the prevalence of dentofacial abnormalities in
children with suspected OSA who have been referred for a PSG at Sick Kids.
.
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Chapter 2 Materials and Methods
2.1 Subjects
Ethics approval was obtained from both the University of Toronto Health
Sciences Research Ethics Board (#31147) and the Hospital for Sick Children's Research
Ethics Board (REB #1000047032). Children referred to the sleep laboratory at the
Hospital for Sick Children, Toronto, Ontario, Canada for overnight PSG between March
2015 to April 2016 were invited to participate in the study (n=100). The subjects were
selected according to the inclusion and exclusion criteria listed in Table 2.1. Informed
consent was obtained verbally and in writing from all study participants and/or their
parents/legal guardian. Study assent was obtained when appropriate.
Table 2.1 Inclusion and Exclusion Criteria.
Inclusion Criteria Exclusion Criteria
• Age 4-18 years
• Referred for an overnight PSG study at the sleep laboratory at the Hospital for Sick Children
• Craniofacial abnormality related to an underlying genetic syndrome
• Children and/or parental caregivers not proficient in English
2.2 Study Procedures
The study procedures are summarized in Table 2.2. A complete description is
provided in the methods section below for each study procedure. All study procedures
were completed at the clinically scheduled overnight sleep study.
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Table 2.2 Summary of Study Procedures
Study Procedure Description Time To Complete
Enrollment and Consent into study Consent obtained from parent/guardian and patient (if appropriate)
3-5 Minutes
Demographic and Clinical Measures Patient and parent information collected 2-3 Minutes
Sleep Questionnaires Spruyt and Gozal Questionnaire Pediatric Sleep Questionnaire
10 Minutes
Clinical Orthodontic Examination All dental examinations completed by Dr. David Simone. Extra-oral and intra-oral exam data collected.
5-10 Minutes
Polysomnogram* PSG undertaken by trained technologists according to the international guidelines111
8-10 hours
* The polysomnogram was clinically indicated and not a research specific study procedure
2.3.Demographics and Anthropometric Measures
The following demographic and anthropometric information was collected from
each patient: 1) age; 2) date of birth; 3) gender; 4) country of origin of mother; 5) country
of origin of father; 6) body type, 7) height, and (8) weight.
Each patient’s BMI was calculated using the formula BMI = Weight (kg)/ Height2
(m2). Each patient's BMI was then converted into a percentile for the population
according to the patient’s age and gender using the published data by the CDC147. Weight
status category was determined from each patient’s BMI percentile according to the
CDC’s guidelines (Table 2-3)148.
Table 2.3 CDC Weight Categories
Weight Status Category Percentile Range
Underweight Less than the 5th percentile
Normal/Healthy Weight 5th percentile to less than 85th percentile
Overweight 85th to less than the 95th percentile
Obese Equal to or greater than the 95th percentile
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2.4 Sleep Questionnaires
2.4.1 Spruyt and Gozal Questionnaire 107
The Spruyt and Gozal questionnaire was developed in 2012 and intended to be a
screening tool for SDB (see Appendix A). All study participants completed this
questionnaire. The questionnaire consists of six questions.
For the development and validation of the questionnaire, 1,133 urban children
with habitual snoring between the ages of 5 to 9 years of age that had undergone a PSG
were included. This sample was analyzed based on established AHI cutoffs. The
investigators developed a set of six ordered questions that allows for fair discrimination
along the SDB spectrum. The questions can be found in Appendix A.
Questions 1-4 and question 6 use Likert-type responses including: 1) never; 2)
rarely; 3) occasionally; 4) frequently; 5) almost always “Question 5 uses the following
scale with regards to snoring: 1) mildly quiet; 2) medium loud; 3) loud; 4) very loud and ;
5) extremely loud.
The total score for the questionnaire represents the average score of all six
questions, according to the following formula (where Q1= raw score to question 1, Q2 =
raw score to question 2, and so forth): A = (Q1+Q2)/2; B = (A+Q3)/2; C = (B+Q4)/2; D
= (C+Q5)/2; and the cumulative score = (D+Q6)/2. Based on the original validation
study, a score greater or equal to 2.72 out of 4 was indicative of a high risk for OSA107.
2.4.2 Pediatric Sleep Questionnaire
Parents/guardians were also asked to complete the PSQ. The PSQ was developed
and validated for sleep disorders in 2000 by Chervin et al106,108. Chervin et al studied
children aged 2-18 years who had PSG confirmed sleep related breathing disorders
(SRDB). Items thought to be predictive of SRBDs in children were formulated based on
clinical experience. This produced a 22-item questionnaire that was strongly associated
with diagnosis of SRBD (P<0.0001) (see Appendix B). The following options were
available for each of the 22 items on the PSQ: yes, no or don’t know. The number of
symptom-items endorsed positively (“yes”) was divided by the number of items
answered positively or negatively; the denominator therefore excluded items with
missing responses and items answered as don’t know. The result was a score, that ranged
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from 0.0 to 1.0. Scores > 0.33 were considered positive and suggestive of pediatric SDB.
This threshold was based on a validation study demonstrating optimal sensitivity and
specificity at the 0.33 cut-off108.
2.5 Clinical Orthodontic Examination
All study participants underwent a comprehensive, clinical orthodontic
examination by the same examiner (D.S.), blinded to any reported signs and symptoms of
query OSA. The examination consisted of dental, skeletal, functional and esthetic
characteristics which were subdivided into four sections: (1) Frontal View, (2) Profile
View, (3) Functional, (4) Intra Oral. The examination lasted approximately 5-10 minutes.
2.5.1 Frontal View
Table 2.4 outlines the examination in the frontal view. Facial type and lower face
height were categorized as brachycephalic if the lower third was shorter than the average,
mesocephalic if the lower third was longer than the average, or dolichocephalic if the
lower third was much larger than the average. Mandibular symmetry was assessed if the
chin point was deviated from the facial midline, in the absence of a functional shift, and
the relationship of the dental midline to the facial midline. Incisor and gingival display at
both rest and smile were measured clinically using a flexible plastic ruler with 1mm
accuracy.
Table 2.4 Frontal View Examination
Front View
1. Type facial (if borderline, choose mesocephalic)
☐Mesocephalic ☐Brachycephalic ☐Dolichocephalic
2. Lower Face Height ☐Normal ☐Increased ☐Decreased
3. Symmetry ☐Symmetric ☐Mandible shift to Right ☐Mandible shift to Left
4. Dental Midlines (midline – use cusp of upper lip)
Upper : ☐on with facial midline ☐shift to Right ☐ shift to Left; Amount : ____mm
Lower : ☐on with facial midline ☐ shift to Right ☐ shift to Left; Amount : ____mm
5. Incisor display at rest ____mm
6. Gingival display on smile ____mm
7. Incisor display on smile ____mm
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2.5.2 Profile View
Table 2.5 outlines the examination from the profile view. Facial profile was
assessed by measuring the angle formed by a line dropped from soft tissue nasion (i.e.
bridge of nose) to subnasale (i.e. base of the upper lip) and a second line extending from
subnasale to soft tissue pogonion (i.e. chin point). An acute angle would indicate a
convex profile; an obtuse angle would indicate a concave profile; and a straight line
would indicate a straight profile. Lip position was determined relative to a straight line
drawn from the tip of the nose to the most anterior curvature of the soft tissue chin. Lip
strain on closing was assessed by the activity of the mentalis muscle.
Table 2.5 Profile View Examination
Profile View
8. Facial Profile ☐Straight ☐Concave ☐Convex
9. Skeletal position - Maxilla ☐Retrognathic ☐Normal ☐Prognathic
10. Skeletal position - Mandible ☐Retrognathic ☐Normal ☐Prognathic
11. Nasiolabial Angle ☐Normal 90º-100 º ☐Acute (< 90 º) ☐Obtuse (>100 º)
Lip Position:
12. With respect to esthetic line: Upper lip
☐Normal ☐Retrusive ☐Protrusive
13. With respect to esthetic line: Lower lip ☐Normal ☐Retrusive ☐Protrusive
14. Lip strain to close ☐Yes ☐No
2.5.3 Functional
Table 2.6 outlines the Functional Assessment portion of the examination. Tonsil
size was evaluated according to the Standardized Tonsillar Hypertrophy Grading
Scale149. Tonsil size 0 denoted surgically removed tonsils. Size 1 implied tonsils hidden
within the pillars. Tonsil size 2 implied the tonsils extending to the pillars. Size 3 tonsils
were beyond the pillars but not to the midline. Tonsil size 4 implied tonsils extend to the
midline149.
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Table 2.6 Functional Assessment
Functional
15. Tonsils ☐Removed ☐1+ ☐2+ ☐3+ ☐4+ (kissing tonsils)
16. History of Mouth Breathing
☐Yes: If YES specify: ☐During Day Time ☐During Night Time ☐ No
2.5.4 Intra-Oral
Table 2.7 outlines the intra-oral portion of the clinical examination. The intra-oral
examination included both vertical and horizontal discrepancies, molar and canine
Angle’s classification, presence of crossbites, and maxillary and/or mandibular crowding
or spacing.
Angles classification of occlusion was assessed for both left and right sides of the
dentition. Subjects in the permanent dentition were classified as having a Class I, Class
II, or Class III malocclusion. Class I occlusion is defined as the mesiobuccal cusp of the
permanent maxillary first molar occluding in the buccal groove of the permanent
mandibular first molar. Class II malocclusion is defined as the mesiobuccal cusp of the
permanent maxillary first molar occluding from a half to full cusp mesial to the buccal
groove of the permanent mandibular first molar. Subjects were classified as Class III
when the mesiobuccal cusp of the permanent maxillary first molar occluded from a half
to full cusp distal to the buccal groove of the permanent mandibular first molar. Subjects
in the primary or mixed dentition were classified as flush terminal plane, mesial step, or
distal step occlusion. Flush terminal plane is defined when the distal surfaces of maxillary
and mandibular primary second molars that lie in the same vertical plane. Mesial step is
defined when the primary mandibular 2nd molar is mesial in relation to the maxillary 2nd
molar and distal step when the primary mandibular 2nd molar is posterior to the distal
surface of the maxillary 2nd molar.
The presence of deep-bites, open-bites, crossbites, and scissor-bites as well as
crowding, were assessed and classified according to the method described by Björk et al.
(1964)150. Vertical excess (i.e. overbite) was measured by taking the average
measurement of both central incisors. Overbite was expressed as the percentage that the
upper incisors vertically overlap the lower incisors. Horizontal excess (i.e. overjet) was
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also measured by taking the average measurement of both central incisors and measuring
the horizontal (anterior-posterior) overlaps of the maxillary central incisors over the
mandibular central incisors. Posterior crossbites were recorded if the buccal cusp of the
upper tooth occluded edge-to-edge, or lingually, to the buccal cusp of the corresponding
lower tooth. Posterior crossbites included cross bites of the primary or permanent molars
and canines as well as permanent premolars. Crowding or spacing of the arch was
evaluated by calculating the amount of overlap or space between the interproximal
contacts of erupted teeth. In mixed dentition, this was done with the assumption that
unerupted permanent canines, first premolars and second premolars will occupy 7mm of
the mesio-distal arch dimension. The overall crowding or spacing was divided into mild
(1-3 mm), moderate (4-9 mm), or severe (>10 mm). Intercanine width and intermolar
width was measured using a Boley gauge with 0.01mm accuracy. Intercanine width was
measured from the cusp tips of the maxillary right and left primary and permanent
canines. Intermolar width was measured from the junction of the lingual groove at the
gingival margin between the maxillary left and right primary second molars and
permanent first molars.
The Index of Orthodontic Treatment Need (IOTN) esthetic scale ranks
malocclusion in terms of the perceived esthetic impairment in order to identify those who
would most likely benefit from orthodontic treatment151.
Table 2.7 Intra-Oral Examination
Intra oral
17. Oral Habits ☐Yes ☐No If YES, since When :____________years
Which? ☐Nail Biting ☐Biting lip/cheek ☐Bruxism ☐Sucking Thumb/finger ☐Other:______________________
18. Horizontal Excess (taken at average of both central incisors, labial to labial)
Overjet: ☐☐☐mm
19. Vertical Excess (taken at average of both central incisors, labial to labial)
Overbite: ☐☐☐%
20. Anterior OpenBite Open bite: ☐☐☐mm
21. Posterior Openbite R ☐☐☐mm
22. Posterior OpenBite L ☐☐☐mm
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23. Odontogram 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8
E D C B A A B C D E
E D C B A A B C D E
8 7 6 5 4 3 1 1 2 3 4 5 6 7 8
24. Dental crossbite (including edge-to-edge bite)
Anterior crossbite: ☐Yes; If YES, # of maxillary teeth involved: ____ ☐No
Posterior crossbite: ☐Yes ☐Unilateral; If YES, # of maxillary teeth involved: ___
☐Bilateral
☐No
25. Narrow Palate ☐Yes ☐No
26. CR/CO shift ☐Yes, specify: ☐Posterior - anterior ☐Vertically
☐To the right ☐To the left
☐No
27. Intermolar distance (measured from mid-palatal groove @ gingival margin)
☐☐☐mm
28. Intercanine distance (measured from cusp tip)
☐☐☐mm
29. Tongue size ☐Normal ☐Microglassia ☐Macroglossia
30. Arch Shape Upper: ☐U shape ☐V shape Lower : ☐U shape ☐V shape
31. Palatal Depth ☐☐☐mm
32. Stage of dentition ☐Primary ☐Mixed ☐Permanent (No primary teeth present)
33. Molar Classification (according to R and L sides)
Permanent: (<1/2 cusp = cl.1) Right: ☐I ☐II ☐III Left: ☐I ☐II ☐III
Primary/mixed: Right: ☐Mesial step ☐Flush ☐Distal Step Left : ☐Mesial step ☐Flush ☐Distal Step
34. Canine Classification (<1/2 cusp = cl.1)
Right: ☐I ☐II ☐III Left: ☐I ☐II ☐III
35. Space Analysis ☐crowding Upper: ☐<3 mm ☐4-9 mm ☐>10mm
Lower: ☐<3 mm ☐4-9 mm ☐>10mm ☐spacing
Upper: ☐<3 mm ☐4-9 mm ☐>10mm Lower: ☐<3 mm ☐ 4-9 mm ☐>10mm
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36. IOTN esthetic scale (match for overall occlusal attractiveness)
2.6 Polysomnogram
Subjects underwent a standard level one overnight baseline PSG using XLTEC
(Oakville, Canada) data acquisition and analysis system. Sleep architecture and
respiratory data were assessed 27 and information was obtained from PSG and scored
according to the AASM scoring guidelines by a registered polysomnogprahic
technician28. A standard overnight PSG lasting approximately 8-10 hours included a 4-
lead EEG (C3, C4, O1, and O2), two bilateral EOG leads referenced to A1 or A2, one
submental and two tibial EMGs. Respiratory measurements included chest wall and
abdominal movement using inductance pneumography; airflow using a nasal cannula
connected to a Nasal Pressure Airflow (NPAF) by Braebon; oxygen saturation (SaO2)
using a Massimo pulse oximeter (Irvine, CA); transcutaneous carbon dioxide
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measurement (TcCO2) using a LINDE carbon dioxide sensor (Munich, Germany). Video
and audio recordings were obtained for each study. The raw data from the
polysomnograms were scored according to the AASM guidelines, as is current clinical
practice152. Scoring involved the quantification of sleep staging, respiratory events,
oxygen saturations and carbon dioxide recordings. Sleep architecture was assessed by
standard techniques. Information obtained from each PSG included: sleep onset latency
and REM onset latency, total sleep time, sleep efficiency, time spent in each sleep stage
(percentage), and number and classification of arousals and snoring. Respiratory events
included obstructive apneas and hypopneas, mixed apneas as well as central apneas and
hypopneas.
The diagnosis and severity of OSA in children was based on the frequency of
obstructive apneas, obstructive hypopneas, mixed apneas, central apneas and central
hypopneas per hour during sleep as well as gas exchange characteristics. These were
recorded as the obstructive apnea-hypopnea index (OAHI), central apnea-hypopnea index
(CAI), baseline mean oxygen saturation and percentage of time the C02 is >50mmHg.
OSA and central apnea (CA) severity will be graded according to accepted clinical
criteria. An OAHI of <1.5 and CAI <1 is normal, an OAHI of >1.5 to <5 and CAI of >1
to <5 indicates mild OSAS and CAI, an OAHI or CAI of >5 to <10 indicates moderate
OSA and CA, and an OAHI or CAO of ≥10 indicates severe OSA and CA152. Nocturnal
hypoventilation (C02 recording >50mmHg for >25% of the night), if present, was
reported from the PSG. All PSGs were reported by one of the three clinical sleep
physicians at The Hospital for Sick Children.
2.7 Statistical Analysis
Descriptive statistics were used to summarize the study results. Intra-rater
reliability testing was assessed for the orthodontic clinical examination. ICC was used for
the continuous rating scale and Kappa statistics for the categorical. 95% confidence
intervals are given for the estimates.
To calculate intra-rater reliability, ten patient records from the Graduate
Orthodontic Clinic of the University of Toronto were randomly selected as the sample for
error analysis. An orthodontic examination was performed on 10 different patients at 2
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different time points, 6 months apart, using the same full orthodontic methodology
(photographs, radiographs and study models). After 6 months, the orthodontic
examination was repeated on the same 10 patients using the same full orthodontic
records. Intra-rater reliability was calculated using the student’s t-test for linear
measurements and percent agreement for categorical measurements.
Data (for the primary analysis) are presented as the mean + standard deviation for
continuous variables and as percentages for categorical variables. Independent
Students t tests were used to compare continuous data and Analysis of Variance
(ANOVA) was used to compare differences between multiple (more than 2) groups. Chi-
square test was used to compare the categorical data. ROC analysis was used to find the
area under the curve, sensitivity, specificity and the confidence around them. Odds ratios
(OR) associated with the presence or absence of characteristics and mean values with
95% CI values were also calculated. Univariate and Multiple Logistic regression was
used to assess the relationship between independent predictor variables and binary
outcomes (OSA). Variables were considered significant at the 5% significance level.
Data were analyzed using SAS/STAT Software, version 9.4 (North Carolina).
2.8 Study Outcomes
The primary outcome was the prevalence of dentofacial abnormalities and
malocclusions in a cohort of children with and without obesity who were referred for a
polysomnogram because of a history of query OSA. Our secondary outcome measure
was the identification of clinical factors that can predict the obstructive apnea-hypopnea
index (OAHI), a measure of the OSA severity, in this referred cohort of children.
2.9 Hypothesis
Our study hypothesis was that there will be an increased prevalence of dentofacial
abnormalities and malocclusions in children with and without obesity with a PSG
diagnosis of OSA as compared to those without a PSG diagnosis of OSA.
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Chapter 3 Results
3.1 Intra-rater Reliability
A total of 29 data collection points were used to determine the intra-rater
reliability. The results for percent agreement for categorical and continuous variables
between the two different time points were assessed using kappa and intraclass
correlation coefficients (ICC), respectively (see Table 3.1). To interpret our results we
used a benchmark cut-off proposed by Landis and Koch:153 Cohen’s kappas ≥ 0.80
represent excellent agreement; coefficients between 0.61 and 0.80 represent substantial
agreement; coefficients between 0.41 and 0.61 moderate agreement; and <0.41 represent
fair to poor agreement.
Table 3.1 Intra-rater reliability. Percent agreement, Kappa and Intraclass Correlation Coefficient of repeated orthodontic examination measurements recorded 6 months apart
Measurement Percent Agreement (%) kappa
Profile 100 1.00
Symmetry 100 1.00
Anterior Openbite 100 1.00
Crossbite 100 1.00
Maxillary Teeth Involved 100 1.00
Posterior Openbite 100 1.00
Stage of Dentition 100 1.00
Permanent Molar Classification Right 100 1.00
Permanent Molar Classification Left 100 1.00
Spacing Mandible 100 0.76
Spacing Maxilla 100 0.66
Skeletal Position Maxilla 90 0.69
Upper Lip with respect to E-Line 90 1.00
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Lower Lip with respect to E-line 90 1.00
Facial Type 90 1.00
Mandibular Arch Shape 90 1.00
Canine Classification Right 90 0.69
Canine Classification Left 90 0.69
Upper Dental Midline 80 0.56
Lower Dental Midline 80 0.61
Skeletal Position Mandible 80 0.69
Maxillary Arch Shape 80 0.60
Nasiolabial Angle 80 0.76
Lower Face Height 80 0.60
Narrow Palate 70 0.35
ICC 95% Confidence Interval
Lower Bound Upper Bound
Overjet (mm) 0.90 0.65 0.98
Overbite (% overlap of incisors) 0.98 0.91 0.99
Intermolar Distance (mm) 0.94 0.79 0.99
Intercanine Distance (mm) 0.96 0.86 0.99
Overall, the agreement for the categorical variables assessed ranged from
0.35(poor agreement) to 1.0 (excellent agreement). Profile, symmetry, anterior openbite,
crossbite, posterior openbite, stage of dentition and molar classification had the highest
Cohen’s kappa (k=1.0), while upper dental midline and narrow palate had the lowest (k=
0.56 and k= 0.35). All continuous measurements had excellent agreement (ICC ranging
from 0.90-0.98).
3.2 Study Participants
One hundred and two children were screened for the study. Two patients declined
study participation. A reason for declining consent was not given. One hundred children
with a mean (standard deviation) age 10.5 (SD 3.8) years participated in the study over
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the recruitment period of 13 months (March 2015 - April 2016). The subjects were
divided into five different groups (see Table 3.2) based on: 1) PSG diagnosis of OSA, 2)
CDC weight status category (BMI percentile range) and 3) history of treatment with PAP
therapy.
Based on the PSG findings, subjects were divided into an OSA group (OAHI >1.5
events per hour) and a non-OSA group (OAHI <1.5 events per hour). On the basis of
weight status category, BMI- for-age percentile growth charts were used to divide
subjects into a non-obese group (BMI< 95th percentile) and an obese group (BMI > 95th
percentile). The fifth group included children that were prescribed PAP therapy.
Table 3.2 Subject Groups
Group # Group Category
1 Non-Obese and No OSA
2 Non-Obese and OSA
3 Obese and No OSA
4 Obese and OSA
5 PAP treatment
See Table 3.3 for the demographic information for the four study cohorts,
excluding the PAP treatment group. The mean BMI, BMI percentile, height, weight, and
presence of mouth breathing were significantly different between the cohorts. The Non-
Obese and OSA group had the highest percentage of snorers (90.7%), mouth breathers
(100%), and children with increased tonsillar size> 3 (50%). However, mouth breathing
was not statically significant between the cohorts (p=0.062).
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Table 3.3 Demographics of the Four Study Cohorts (excluding PAP group)
Table 3.4 compares the demographic information for the subjects with and
without OSA (excluding the PAP group). When the subjects were divided based on OSA
diagnosis, there were no significant demographic differences between the groups.
Non-Obese and No OSA
Non-Obese and OSA
Obese and No OSA
Obese and OSA
P value
Sample Size (n) 21 11 28 27
Age (years) 9.4 (3.6) 8.18(4.69) 10.93(3.74) 11.0(3.92) 0.13
Male (%) 17 (81) 7(63.6) 16(57.1) 21(77.8) 0.12
BMI (kg/m2) 19.54 (3.85) 17.17 (3.17) 30.53 (8.25) 33.39(9.73) <0.0001
BMI Centile 75.81 (20.45) 53.27 (26.63) 98.11 (1.13) 98.11(1.42) <0.0001
Height (cm) 136.33 (22.24) 128.55 (25.01) 150.07 (17.34) 150.63(20.10) 0.0038
Weight (kg) 39.22 (20.26) 31.0 (19.58) 70.73(31.59) 108.42(33.31) <0.0001
Snoring 14 (66.7) 10 (90.9) 22(78.6) 24(88.9) 0.20
Mouth Breather 15(71.4) 11 (100) 22(78.6) 15(55.6) 0.0355
Increased Tonsillar Size >3 6(28.6) 5(50) 3(10.7) 5(18.5) 0.06
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified.
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Table 3.4 Demographics of OSA vs. No OSA Groups (excluding PAP group)
OSA
(n=38)
No OSA
(n=49)
p-value
Age (Years) 10.2(4.3) 10.3(3.7) 0.91
Male 28(73.7) 33(67.4) 0.52
BMI (kg/m2) 28.69(11.17) 25.82(8.64) 0.19
BMI Centile 85.13(24.85) 88.55(17.30) 0.45
Height (cm) 144.2(23.58) 144.2(20.55) 0.99
Weight (kg) 66.51(41.54) 57.23(31.31) 0.26
Snoring 34(89.5) 36(73.5) 0.06
Mouth Breather 26(68.4) 37(75.5) 0.46
Increased Tonsillar Size >3 10(27.0) 9(18.4) 0.34
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified.
3.3 Polysomnography Results
See Table 3.5 for a summary of the PSG findings across the four cohorts.
Significant findings included sleep state distribution %N1 sleep, sleep stage distribution
% REM sleep, total arousal index, respiratory events arousal index, oxygen desaturation
index, maximum respiratory rate, mean respiratory rate, maximum transcutaneous carbon
dioxide (tcCO2), percent of sleep time with end-tidal carbon dioxide (EtCO2) above
50mmHg,OAHI index and AHI index. The OAHI and AHI were significantly different
across the four groups and were the highest in the Obese and OSA group with a mean
(SD) OAHI of 12.31(15.42), (p=<0.0001) and 13.15(15.33), (p=<0.0001), respectively.
Table 3.5 PSG Results across the Four Cohorts (excluding PAP group)
Non-Obese and No OSA
Non-Obese and OSA
Obese and No OSA
Obese and OSA P value
Total Sleep Time (TST) (minutes) 426.7 (45.6) 414.9 (66.7) 360.2 (113.5) 365.1 (63.1) 0.14
Sleep Efficiency (%) 84.8 (9.1) 87.0 (10.1) 81.8 (16.3) 82.9 (11.2) 0.65
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Sleep stage distribution % N1 4.5 (3.0) 4.9 (3.5) 5.5 (3.3) 7.6 (4.9) 0.03
Sleep stage distribution % N2 46.57 (3.0) 46.6 (4.3) 46.6 (11.9) 49.1 (9.0) 0.74
Sleep stage distribution % N3 29.5 (3.0) 28.1 (7.1) 29.9 (9.8) 27.8 (9.1) 0.80
Sleep stage distribution % REM 19.4 (3.1) 20.5 (6.3) 18.0(5.0) 15.5 (6.6) 0.04
Wake after sleep onset (WASO),
(minutes)
36.9 (3.2) 31.4 (31.4) 38.5 (59.5) 53.0 (42.4) 0.45
Sleep onset latency, (minutes) 29.4 (3.2) 21.7 (21.7) 37.3 (27.1) 25.7 (30.1) 0.37
REM latency, (minutes) 128.40 (53.7) 139.6 (73.7) 154.8 (72.8) 141.6 (59.2) 0.55
Total arousal index (# events/
hour) 9.8 (2.3) 15.4 (4.5) 9.3 (4.2) 17.6 (8.1) <0.0001
Spontaneous arousal index
(#events/hour) 11.8 (13.3) 8.6 (3.4) 7.9 (3.5) 9.2 (3.9) 0.32
Respiratory events arousal index
(#events/ hour) 0.6 (.6) 6.5 (4.7) 0.8 (0.8) 7.9 (7.7) <0.0001
Oxygen saturation mean (%) 97.8 (0.6) 97.4 (0.9) 97.9 (0.9) 97.1 (2.6) 0.22
Oxygen saturation minimum, (%) 91.5 (2.8) 87.6 (9.7) 92.3 (3.9) 86.5 (13.0) 0.05
Oxygen desaturation index, (#
events/hour) 0.8 (0.6) 4.5 (6.0) 0.8 (0.8) 10.0 (22.0) 0.03
Time spent ≤ 90% oxygen
saturation (minutes) 0.03 (0.06) 2.0 (5.7) 0.0 (0.1) 10.2 (36.5) 0.24
Respiratory rate mean (bpm) 17.0 (2.0) 15.0 (5.1) 16.9 (2.4) 18.3 (3.3) 0.03
Respiratory rate minimum (bpm) 13.5 (2.2) 13.8 (2.3) 13.8 (2.4) 14.6 (2.4) 0.41
Respiratory rate maximum (bpm) 20.6 (2.7) 21.1 (1.6) 20.7 (3.7) 23.9 (4.5) 0.005
Heart rate mean (bpm) 80.0 (12.3) 79.6 (14.9) 75.2 (11.4) 78.0 (10.1) 0.13
Heart rate minimum (bpm) 53.7 (7.7) 58.0 (11.2) 55.2 (7.8) 57.7 (8.4) 0.32
Heart rate maximum (bpm) 109.3 (13.6) 121.5 (15.1) 114.2 (20.4) 111.7 (11.1) 0.20
EtCOⁿ minimum (mmHg) 33.4 (4.7) 30.9 (3.4) 31.2 (5.5) 29.8 (9.3) 0.39
EtCOⁿ maximum (mmHg) 49.7 (2.5) 50.2 (6.7) 50.2 (3.4) 52.3 (7.7) 0.42
TcCOⁿ minimum (mmHg) 35.1 (4.2) 37.3 (11.0) 33.7 (4.9) 34.2 (9.1) 0.54
TcCOⁿ maximum (mmHg) 47.1 (4.0) 55.5 (19.34) 47.7 (4.3) 49.0 (6.7) 0.048
% TST EtCO2 > 50 mmHg 0.4 (0.4) 29.3 (0) 1.8 (3.5) 4.8 (12.8) 0.03
% TST TcCO2 > 50 mmHg 14.1 (15.7) 28.7 (0) 4.9 (10.9) 14.6 (22.1) 0.44
CAI (#events/ hour) 0.62 (0.46) 0.87 (1.34) 0.66 (0.77) 0.67 (0.91) 0.88
OAHI (#events/ hour) 0.40 (0.63) 9.46 (9.20) 0.51 (0.59) 12.31 (15.42) <0.0001
AHI (#events/hour) 1.12 (0.71) 10.51 (9.35) 1.18 (0.88) 13.15 (15.33) <0.0001
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified. TST, total sleep time; REM, rapid eye movement; WASO, wake after sleep onset; bpm, beats per minute; EtCOⁿ, end-tidal carbon dioxide; TcCOⁿ, transcutaneous carbon dixode
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Table 3.6 summarizes the PSG findings for the subjects with and without OSA
(excluding PAP group). The significant differences between these groups were sleep
stage distribution % N1 sleep, total arousal index, respiratory events arousal index,
minimum oxygen saturation , oxygen desaturation index, maximum respiratory rate ,
heart rate mean, OAHI and AHI Index.
Table 3.6 PSG results of OSA vs. No OSA Groups (excluding PAP group)
OSA
(n=38)
No OSA
(n=39)
P value
Total Sleep Time (TST) (minutes) 379.5(67.26) 376.9(93.70) 0.88
Sleep Efficiency (%) 84.09(10.88) 83.08(13.65) 0.71
Sleep stage distribution % N1 6.86(4.65) 5.07(3.21) 0.0469
Sleep stage distribution % N2 48.33(7.98) 46.60(10.40) 0.40
Sleep stage distribution % N3 27.84(8.46) 29.75(9.19) 0.32
Sleep stage distribution % REM 16.98(6.79) 18.59(4.65) 0.22
Wake after sleep onset (WASO) (minutes) 46.71(40.37) 37.83(47.85) 0.36
Sleep onset latency, (minutes) 24.56(27.71) 33.88(30.17) 0.14
REM latency, (minutes) 141.0(62.68) 143.5(63.70) 0.86
Total arousal index (#events/hour) 16.99(7.30) 9.48(3.53) <0.0001
Spontaneous arousal index (#events/hour) 9.02(3.76) 9.55(9.21) 0.72
Respiratory events arousal index (#events/hour) 7.51(6.94) 0.72(0.74) <0.0001
Oxygen saturation mean (%) 97.16(2.20) 97.86(0.78) 0.07
Oxygen saturation minimum (%) 86.82(12.01) 91.93(3.45) 0.01
Oxygen desaturation index (#events/hour) 8.42(18.91) 0.80(0.71) 0.02
Time spent ≤ 90% oxygen saturation (minutes) 7.82(30.96) 0.02(0.06) 0.13
Respiratory rate mean (bpm) 17.35(4.17) 16.90(2.20) 0.55
Respiratory rate minimum (bpm) 14.36(2.36) 13.67(2.31) 0.17
Respiratory rate maximum (bpm) 23.0.5(4.10) 20.67(3.28) 0.004
Heart rate mean (bpm) 78.50(11.52) 73.35(11.87) 0.045
Heart rate minimum (bpm) 57.78(9.12) 54.53(7.68) 0.08
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Heart rate maximum (bpm) 114.5(13.01) 112.1(17.78) 0.49
EtCOⁿ minimum (mmHg) 30.12(7.91) 32.08(5.23) 0.25
EtCOⁿ maximum (mmHg) 51.65(7.34) 49.99(3.08) 0.26
TcCOⁿ minimum (mmHg) 35.12(9.65) 34.29(4.63) 0.63
TcCOⁿ maximum (mmHg) 50.93(12.01) 47.44(4.16) 0.10
% TST EtCO2 > 50 mmHg 6.72(13.98) 1.50(3.16) 0.21
% TST TcCO2 > 50 mmHg 15.51(21.64) 6.35(11.47) 0.17
CAI (#events/hour) 0.73(1.04) 0.65(0.65) 0.64
OAHI (#events/hour) 11.49(13.85) 0.46(0.60) <0.0001
AHI (#events/hour) 12.38(13.80) 1.15(0.80) <0.0001
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified. TST, total sleep time; REM, rapid eye movement; WASO, wake after sleep onset; bpm, beats per minute; EtCOⁿ, end-tidal carbon dioxide; TcCOⁿ, transcutaneous carbon dioxide
3.4 Questionnaire Results
3.4.1 Spruyt and Gozal Questionnaire
A total of 77 subjects were included in the statistical analyses for the Gozal and
Spruyt questionnaire. 13 subjects were excluded because the patients were using PAP
therapy. 10 questionnaires were excluded to due missing data. Table 3.7 shows the total
number of subjects who scored >2.72 on the Spruyt and Gozal questionnaire across all
four cohorts. The obese groups (No-OSA and OSA) on average had a higher percentage
of subjects who scored higher on the questionnaire (13.64% and 14.77%, respectively)
than the non-obese groups. However, the Spruyt and Gozal questionnaire scores were not
different between the four cohorts (p=0.94).
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Table 3.7 Spruyt and Gozal Questionnaire results across the Four Cohorts
(excluding the PAP therapy group)
Non-Obese and No OSA
Non-Obese and OSA
Obese and No OSA
Obese and OSA
P value
Total Spruyt and Gozal Score >2.72
4 (4.55)
4(4.55)
12(13.64)
13(14.77)
0.94
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified
The specificity and sensitivity for the Spruyt and Gozal questionnaires for the
diagnosis of OSA was calculated from the 2x2 contingency table (see Table 3.8). The
Spruyt and Gozal scores were compared for children with and without OSA. Children
receiving PAP therapy were excluded.
Table 3.8 Frequencies of Spruyt and Gozal Scores of OSA vs. No OSA groups
(excluding PAP group)
OSA
Spruyt and Gozal Score > 2.72
Yes No
Yes 17 16
No 19 25
From the above table, it was found that this questionnaire was able to correctly
identify children who have OSA (AHI>1.5) with a sensitivity of 47.22% and a specificity
of 60.98% . Also, the odds ratio of having sleep apnea with a Spruyt and Gozal score of
greater than 2.72 was 1.40 (95% CI 0.56-3.46, p = 0.47). The odds ratio was not
significant. The graph in Fig 3.1 shows the receiver operating curve (ROC) for the Spruyt
and Gozal questionnaire to correctly diagnose children with and without OSA. The area
under the curve was 0.54. It is evident from the plotted data that the ROC curve closely
approximates a straight line. The Spruyt and Gozal questionnaire was a poor screening
test for OSA in our study cohort.
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Figure 3.1 ROC Curve for the Spruyt and Gozal Questionnaire to Screen for OSA
3.4.2 Pediatric Sleep Questionnaire
13 patients from the cohort were excluded because they were using PAP therapy.
The remaining 87 subjects were included in the PSQ statistical analysis. Questionnaire
scores > 0.33 were considered positive and suggestive of pediatric OSA. This threshold
is based on a validation study that demonstrated that the PSQ's optimal sensitivity and
specificity for the detection of OSA is at this cutoff. 108. Table 3.9 reveals the total
number of subjects who scored >0.33 on the PSQ questionnaire for all four cohorts.
Children with obesity had the highest proportion of children that were PSQ screen
positive but this difference was not significantly difference (p=0.62).
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Table 3.9 Pediatric Sleep Questionnaire Results across the Four Cohorts (excluding
PAP group)
Non-Obese and
No OSA Non-Obese and
OSA Obese and No
OSA Obese and
OSA P value
Total PSQ Score >0.33
16(18.4)
9(10.3)
22(25.3)
19(21.8)
0.62
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified
Specificity and sensitivity for the PSQ to detect OSA was calculated from the 2x2
contingency table (see Table 3.10). The PSQ scores were compared for children with and
without OSA. Children receiving PAP therapy were excluded.
Table 3.10 Frequencies of PSQ Scores of OSA vs. No OSA groups (excluding PAP
group)
OSA
PSQ > 0.33
Yes` No
Yes 28 38
No 10 11
From the above table, it was found that this questionnaire was able to correctly
identify children who have OSA (AHI>1.5) with a sensitivity of 73.88% and a specificity
of 22.45%. Also, the odds ratio of diagnosing OSA based on a PSQ score of greater than
0.33 was 0.8105 (95% CI 0.3025-2.1720, p = 0.68). However, the odds ratio was not
significant. The graph in Fig 3.2 shows the ROC for the PSQ questionnaire to correctly
identify children with and without OSA. The area under the curve was 0.56. It is evident
from the plotted data that the ROC curve closely approximates the straight line. The PSQ
questionnaire was a poor screening test for OSA in our study cohort.
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Figure 3.2 ROC Curve for the PSQ Score Questionnaire to Screen for OSA
3.5 Dentofacial Morphology
Dentofacial characteristics were grouped into variables describing anterior-
posterior, transverse, vertical, and perimeter characteristics of the patient’s morphology.
Table 3.11 summarizes the prevalence of dentofacial morphology characteristics of the
four study cohorts. The only statistically significant differences between the four groups
were overjet (p=0.02), maxillary intermolar width (p=0.02), and maxillary intercanine
width (p=0.0005).
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Table 3.11 Prevalence of Dentofacial Characteristics across the Four Cohorts
(excluding the PAP therapy group)
ANTERIOR-POSTERIOR Non-Obese and No OSA
Non-Obese and OSA
Obese and No OSA
Obese and OSA
P value
Convex Profile 28.6 % 9.1 % 28.6 % 29.6 % 0.97
Retrognathic Mandible 28.6 % 9.1 % 32.1 % 29.6 % 0.92
Anterior Crossbite 9.5 % 9.1 % 25.0 % 18.5 % 0.80
Overjet(mm) 2.7 (1.6) 2.3 (1.1) 1.6 (2.0) 3.3 (2.4) 0.02
Class II Molar 25 % 16.7 % 12.5 % 23.5 % 0.66
Class II Canine 40 % 4.6 % 21.4 % 17.0 % 0.62
Distal Step 38.5 % 18.8 % 41.7 % 24.3 % 0.93
TRANSVERSE & VERTICAL Non-Obese and No OSA
Non-Obese and OSA
Obese and No OSA
Obese and OSA
P value
Dolichocephalic Facial Pattern 0 % 0 % 3.6 % 3.7 % 0.74
Increased Lower Face Height 19.1 % 9.1 % 36.7 % 48.1 % 0.22 Overbite (% overlap of Incisors) 46.7(37.2) 60.0(37.1) 30.9(3.1) 43.7(45.4) 0.21
Anterior Openbite 0 % 9.1 % 10.7 % 0 % 0.16
Posterior Crossbite 14.3 % 2.7 % 17.9 % 11.1 % 0.51
Narrow Palate 9.5 % 18.2 % 39.3 % 18.5 % 0.71
Maxillary Intermolar Width (mm) 36.0 (3.5) 33.9(5.2) 37.7(3.4) 37.8(3.8) 0.02
Maxillary Intercanine Width (mm) 31.2 (2.8) 29.4(3.0) 32.9(2.5) 33.4(3.2) 0.0005
PERIMETER Non-Obese
and No OSA Non-Obese and OSA
Obese and No OSA
Obese and OSA
P value
Maxillary or Mandibular Crowding > 4mm
4.7% 27.3% 32.14% 29.6% 0.36
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified
To better understand the relationship the relationship between SDB and
dentofacial morphology, we evaluated the differences between subjects with OSA (AHI
>1.5; n=38) as compared to those without OSA. (AHI <1.5; n=49). Children receiving
PAP therapy were excluded from this analysis. Table 3.12 summarizes these findings.
The only significant dentofacial difference found between OSA and non-OSA children
was overjet. The mean (SD) overjet in OSA children was 3.0mm(2.14mm) and
2.06mm(1.94mm) in non-OSA children (p=0.04). Although there was only one
statistically significant difference between the two-groups, there was a trend towards
children with OSA having a higher percentage of dolichocephalic facial type, increased
lower face height, and mandibular or maxillary crowding >4mm. Linear measurements
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that were higher in children with OSA included overbite, inter-molar distance and inter-
canine distance.
Table 3.12 Dentofacial Morphology of OSA vs. No OSA Groups (excluding PAP
group)
OSA
(n=38)
No OSA
(n=49)
P value
Dolichocephalic Facial Type 1 (2.6) 1(2.0) 0.74
Increased LFH 14 (36.8) 14(28.6) 0.72
Convex Profile 9 (23.7) 14(28.6) 0.61
Retrognathic Mandible 9 (23.7) 15(30.6) 0.40
Anterior Open Bite 1 (2.6) 3(6.1) 0.63
Anterior Crossbite 6 (15.8) 9(18.4) 0.75
Posterior Crossbite 6 (15.8) 8(16.3) 0.95
Narrow Palate 7 (18.4) 13(26.5) 0.37
Distal Step 7 (18.4) 10(20.4) 0.93
Canine Class II 10 (26.3) 14(28.6) 0.62
Maxillary or Mandibular Crowding >4mm 11 (28.9) 10(20.4) 0.36
Overbite (% overlap of incisors) 48.42(43.34) 37.65(37.57) 0.22
Overjet (mm) 3.0 (2.14) 2.06 (1.94) 0.04
Inter-canine distance (mm) 32.24 (3.63) 32.16(2.69) 0.91
Inter-molar Distance (mm) 36.71 (4.54) 36.96(3.49) 0.77
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified
Univariate analysis was then performed with OAHI > 1.5/hr (i.e. positive
diagnosis for OSA) as the predictor outcome for the various dentofacial characteristics.
Table 3.13 provides the p-values and odds-ratios from the univariate analysis. Overall
there was no statistical significant association between AHI and dentofacial
characteristics.
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Table 3.13 Univariate Analysis for Various Dentofacial Characteristics (excluding
the PAP therapy group)
Variable Odds Ratio 95% Confidence Interval
P -value
Dolichocephalic vs. Mesocephalic Facial Type
Brachycephalic vs. Mesocephalic Facial Type
0.750
0.550
0.032-17.506
0.115-2.625
0.74
Convex vs. Normal Profile Type
Concave vs. Normal Profile Type
0.769
0.765
0.092-6.449
0.087-6.716
0.97
Increased Lower Face Height vs. Normal Face Height
Decreased Lower Face Height vs. Normal Face Height
0.441
0.500
0.174-1.118
0.072-3.477
0.22
Retrognathic vs. Normal Mandible 0.956 0.383-2.386 0.92
Distal Step 0.943 0.268–3.315 0.93
Class II Canine 1.273 0.494–3.276 0.62
Anterior Crossbite 1.157 0.379-3.534 0.80
Posterior Crossbite 0.673 0.206-2.206 0.51
Narrow Palate 0.822 0.298-2.271 0.71
Maxillary or Mandibular Crowding >4mm 0.629 0.235-1.689 0.36
Overbite (% overlap of incisors) 1.005 0.994-1.016 0.21
Overjet (mm) 1.005 0.996-1.570 0.02
Furthermore, to determine if an association existed between dentofacial
morphology and the use of PAP therapy, children with obesity and recently diagnosed
OSA (i.e. not using PAP therapy) were compared to children with obesity and OSA who
have been using PAP therapy for a minimum period of at least 1 year. Table 3.14
summarizes the findings between the two groups. There were no statistical differences
between the two groups.
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Table 3.14 Dentofacial Morphology of Obese & OSA vs. Obese & PAP groups
Obese and OSA (n=27)
Obese CPAP (n=13)
P-Value
Dolichocephalic Facial Type 1(3.70) 0(0) 0.99
Increased LFH 13(48.2) 8(61.5) 0.51
Convex Profile 8(29.6) 5(38.5) 0.58
Retrognathic Mandible 8(29.6) 6(46.2) 0.30
Anterior Open Bite 0(0) 0(0) 0.99
Anterior Crossbite 5(18.5) 6(46.2) 0.13
Posterior Crossbite 3(11.1) 4(30.1) 0.13
Narrow Palate 5(18.5) 2(16.67) 0.89
Distal Step 5(50.0) 1(100) 0.34
Canine Class II 18(66.7) 9(69.23) 0.87
Maxillary or Mandibular Crowding >4mm 3(11.11) 4(31) 0.12
Overbite (% overlap of incisors) 43.70(45.41) 33.08(45.35) 0.49
Overjet (mm) 3.30(2.399) 1.69(2.29) 0.06
Inter-canine distance (mm) 33.41(3.21) 34.38(3.92) 0.44
Inter-molar Distance (mm) 37.85(3.80) 40.31(4.66) 0.11
* Statistics shown for categorical variables are n (%) from the population with available data as continuous variables are mean (SD), unless otherwise specified
A multiple regression model was developed using generated variables with p-
values < 0.05 from the univariate analyses. Table 3.15 demonstrates the multiple
regression analysis.
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Table 3.15 Multiple Regression Model for the Presence of OSA in the Study Cohort
Excluding Children Using PAP Therapy
Variable Odds Ratio 95% Confidence Interval
P -value
Overjet (mm) 1.328 1.001-1.761 0.049
Respiratory Rate Max 1.234 1.018-1.496 0.03
BMI 1.027 0.968-1.089 0.38
Total Arousal Index 1.313 1.137-1.517 0.0002
Overjet, maximum respiratory rate, and total arousal index were significant
predictors of OSA as demonstrated form the multiple regression analysis. The odds ratio
of having an increased overjet and OSA was 1.328 (95% CI 1.001-1.761, p = 0.049). The
odds ratio of having an increased maximum respiratory rate and OSA was 1.234 (95% CI
1.018-1.496, p = 0.03). The odds ratio of having an increased total arousal index was
1.313 (95% CI 1.137-1.517, p = 0.0002). BMI was not a significant predictor for OSA.
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Chapter 4
Discussion
We are reporting on the first pediatric study to systematically describe the
prevalence of dentofacial characteristics in a referred cohort of children with and without
PSG proven OSA using the currently recommended AASM guidelines. A key finding of
our study was that the prevalence of an overjet (i.e. horizontal excess) was significantly
higher in the children with OSA as compared to those without OSA. Furthermore, the
presence of an overjet, maximum respiratory rate, total arousal index all significantly
predicted the presence of OSA in our study cohort.
We evaluated dentofacial morphology in three planes: vertical, transverse, and
anterioposterior. When the study population was subdivided into four groups based on a
diagnosis of OSA and CDC BMI centile criteria for obesity, three dentofacial
characteristics were significantly different between the groups. These included overjet
(i.e. horizontal excess), maxillary intermolar width and maxillary intercanine width.
However, after the study cohort was subdivided based on an OSA diagnosis, only the
presence of an overjet remained clinically significant. This increase in overjet may be
explained by the presence of a Class II skeletal pattern and/or dental pattern, which has
found to be more prevalent in OSA children versus healthy controls142. Also, an increased
overjet in OSA children can be explained by long-term changes in the position of the
head, mandible, and tongue in order to maintain airway adequacy during sleep142.
Our finding of an increased overjet is consistent with previous studies on the
effects on OSA and dentofacial morphology. Pirilä-Parkkinen et al.145 conducted a
similar study in 2008, looking at the effects of SDB on developing dental arches. Their
findings, like ours, found children with OSA had a significantly increased overjet,
however, they also found a reduced overbite, narrower upper arch and shorter lower
dental arch when compared with the controls. The difference in findings may be
explained by the fact that their protocols followed the older guidelines published by the
American Thoracic Society in 1996 for scoring OSA diagnosed by PSG. The use of older
guidelines for scoring OSA may result in over- or under-diagnosis of OSA, leading to
different results based on OSA criteria and diagnosis. Our study used the most up-to-date
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guidelines published by the AASM88 and found overjet as the only significant
dentofacial predictor of OSA.
Katyal et al39 conducted a systematic review in 2013 on dentofacial morphology
using lateral cephalograms in pediatric OSA . Katyal et al. found an increase in weighted
mean differences in the ANB angle of 1.64 degrees (P<0.0001) and 1.54 degrees
(P<0.00001), respectively, in children with OSA and primary snoring, compared with the
controls. The authors concluded that an increased ANB angle of less than 2 degrees in
children with OSA and primary snoring, compared with the controls, could be regarded
as having marginal clinical significance. Though our study did not look at cephalometric
measurements and ANB angles, our finding of increased overjet was found to be
significantly associated with a higher AHI, but it is not yet clear if this result is clinically
significant.
An interesting finding of our study was the incidence of convex profile,
retrognathic mandible, anterior open bite, anterior crossbite, posterior crossbite, narrow
palate, distal step and Class II canine were higher in the non-OSA group when compared
with OSA group. This is unexpected as based on the results of the systematic review, the
prevalence of these dentofacial characteristics would be expected to be higher in the
group with OSA. However, our findings may be explained by the fact that pediatric OSA
is a multifactorial disease and that craniofacial morphology is frequently not the only
factor contributing to the disease process154.
Although, PAP therapy is an effective therapy for OSA in children, there are
some notable long-term sequelae that have been reported in the literature. The
craniofacial skeleton in the growing child is responsive to changing functional demands
and environmental factors. Orthopedic modification of facial bones through the sustained
application of near-constant forces over long periods of time has been a mainstay of
orthodontic and dentofacial orthopedic therapy155. The successful use of PAP therapy
requires the application of such forces to the midface area. This prompts concern about
potential side effects on antero-posterior skeletal development in that area. The possible
effect of PAP therapy might depend on the skeletal age at which treatment begins. The
rate of normal forward and downward displacement of the midface varies with age129. A
review of the literature reveals that greater skeletal changes in the midface are possible in
younger patients and children because the early mixed dentition is particularly vulnerable
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to the effects of PAP therapy on the development of the face, jaw, and teeth88,156,157. In
our study, the ages of children receiving PAP therapy ranged from 4 to 16 years of age.
However, all the subjects, with the exception of one child, were between 10 to 16 years
of age. Thus the majority of children were in the late-mixed to permanent dentition phase.
Case reports have suggested that long-term treatment with CPAP or BPAP during
early childhood carries a high risk of facial growth impairment, in particular, midface
hypoplasia and Class III malocclusions127,128. However, more recently, a small sample
size, cross-sectional study failed to show any statistically significant difference between
long-term PAP use and craniofacial morphologic pattern in children with persistent
OSA129. Our study was in line with this most recent cross-sectional study. We did not
find any statistically significant differences between the children with obesity not using
PAP therapy and children with obesity, using PAP therapy. However, all of the children
prescribed PAP therapy were greater than 10 years of age (with the exception of one
subject), and, therefore, the majority of the skeletal structures have already developed.
Interestingly, anterior crossbite was significantly more prevalent in the PAP group
(46.2% vs. 18.5%), though not statistically significant (p=0.13). This can be explained by
the increased force of the facemask on the anterior teeth. This is an area of future study to
determine of the anterior crossbite continues to progress in this cohort with subsequent
years of PAP therapy usage.
The intra-rater reliability of the orthodontic examinations for dentofacial
characteristics demonstrated excellent agreement for the majority of the measurements
with (K ≥ 0.80). The intra-rater reliability was poor for narrow palate (k=0.35). The
continuous measurements for overjet, overbite, intermolar and intercanine distance had
excellent agreement with ICC ranging from 0.90-0.98. Therefore, based on our results,
the orthodontic clinical examination seems to be a quick, reliable assessment that could
be done in any busy sleep medicine clinic. Furthermore, there is the potential to translate
this clinical examination traditionally performed by skilled dentists into a screening
examination that could be performed by sleep medicine clinicians.
The high reliability of the clinical dental examination has been previously
described in the literature. Dwokrin et al.158 demonstrated excellent reliability of
assessing molar classification in adults (K=0.78), We reported perfect agreement
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(K=1.0) for the molar classification in the permanent dentition. A possible explanation
for this discrepancy is that Dworkin et al. used a more rigorous scale divided into ¼ cusp
increments to diagnose molar classification whereas out study used ½ cusp increments.
Carvalho et al. has also previously reported the inter- and intra-observer agreement for
diagnosis of dental malocclusion; the Cohen’s kappa coefficients ranged from 0.808
(overbite ≥ 4mm, yes or no), to 1.0 (openbite, yes or no)159.
With regards to orthodontic diagnosis and classification, it is possible that several
indicators of malocclusion (eg. molar classification, canine classification, overjet,
overbite) which directly affect the extra-oral facial characteristics (i.e. facial type, profile,
etc) may change spontaneously due to difference in mandibular position as determined by
the patient and/ or examiner160. However, since our percent agreement among
measurements were based upon orthodontic records as opposed to chair-side
examination, the disagreement in measurements between the two different time-points
were most likely due to differences in observation rather than differences in examination
technique.
Our study sample as a whole had a 74% prevalence of snoring, which is much
higher than the reported 7 to 28% prevalence of primary snoring in the literature.88
However, our study cohort was a referred population of children with suspected OSA
rather than a population based cohort. More specifically, our sample had a higher
percentage of snorers in both obese groups and OSA groups, of which a significant
difference was found. When analyzing the overall score for the 6-item questionnaire to
predict OSA, there was a higher prevalence of predictive scores in the obese groups
(OSA and Non-OSA) than the non-obese groups (OSA and non-OSA). However, the
sensitivity and specificity of the Spruyt and Gozal questionnaire used in our study was
47.22% and 60.98%, respectively, making it a poor predictor of OSA. This is somewhat
comparable to the sensitivity, 59.03%; and specificity, 82.85%, reported by Spruyt et al
94 in their questionnaire validation study. Similar trends were seen when analyzing the
overall scores from the PSQ. The obese groups (non-OSA and OSA) showed a
prevalence of 25.3% and 21.8%, respectively, however, with no statistical significance.
The sensitivity and specificity was also poor at 73.88% sensitivity and 22.45%
specificity. This supports the general consensus in the literature stating that patients’
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complaints of snoring alone is insufficient to discriminate apneic and non-apneic
snorers161-163. In conclusion, our study clearly demonstrates that sleep questionnaires have
limited accuracy as screening tools for OSA in children.
There were no statistically significant differences between the groups in age,
gender, and percentage of mouth breathers. In an epidemiological study done in 2008 by
Lumeng et al. in children with OSA, the available data appeared insufficient to prove that
SDB differs systematically by age 15. This is in line with our findings. Lumeng et al also
reported that there is a higher percentages of boys who are affected by SDB (50-100%
higher) than girls15. Though our results are non-significant for gender, there is a much
higher percentage of boys in both OSA groups, 63.6% vs. 36.4% (Non-Obese) and
77.8% vs. 22.2% (Obese). The prevalence of mouth breathing in our study was 71%,
which is much higher than was Izu. et al164 found of 42% in OSA children. Though
mouth breathing was most prevalent in the non-obese/OSA group (100%), there was a
high prevalence amongst all the groups.
There were a few notable limitations to our study and the results should be
interpreted with caution. First, it was a cross-sectional study with a relatively small
sample size in each of our cohorts, and significant differences could be identified with a
larger sample size.. Our recruitment potential was limited due to the fact that we were
only including children with and without obesity that did not have any other
comorbidities. Over 80% of the children seen in the sleep center at SickKids have
comorbidities. Secondly, we did not have a true 'non snoring' control group as our non
OSA comparator group also had symptoms suggestive of OSA warranting a referral to a
sleep center but did not have a PSG diagnosis of OSA. Finally, our study used clinical
examination as the sole method of evaluating dentofacial morphology. Although, a more
objective measure of dentofacial morphology would have been beneficial to directly
calibrate the clinical examination, the authors could not justify exposing children to
radiation for screening purposes. From the literature, orthodontic examinations have been
shown to have high intra- and inter-observer reliability. 145,159 In addition, the author
performed all of the orthodontic examinations and was demonstrated to have high intra-
rater reliability. Therefore, we could not justify the radiation exposure from lateral
cephalograms or cone beam Computed Tomograms for our study participants.
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Future studies in this area of research would be to conduct a similar study but
with a larger sample size and a true control group, using objective forms of data
collection such as lateral cephalograms and/or facial scans. Theoretically this would give
more credibility for cause and effect, however, due to the relative scarcity of sleep labs
and the long wait times for a polysomnogram, it would be highly unethical to use this
resource on healthy children for the purpose of research, while those with signs and
symptoms of SDB are expected to wait. Since overjet was the most significant
dentofacial predictor of OSA, areas of future study would also include a longitudinal
assessment of overjet pre and post adenotonsillectomy. In addition, the severity of the
OSA based on PSG could be assessed pre and post treatment of overjet in children with
OSA. Finally, a longitudinal assessment of children using PAP therapy starting from a
young age (<6 years of age) would be able to better demonstrate if any possible changes
occur in craniofacial development from the use of prolonged PAP therapy.
In summary, the results from the studying of intra-rater reliability of clinical
measures of malocclusion and facial characteristics demonstrated excellent agreement for
the majority of the measurements. Sleep questionnaires proved to be unsuccessful at
predicting the presence of obstructive sleep apnea. OSA was only statistically related to
horizontal excess (overjet). All other dentofacial characteristics were not statistically
significant. Even though overjet was found to be statistically significant, the clinical
significance between the mean difference in overjet between the OSA and Non-OSA
groups is yet to be determined. There were no significant differences in dentofacial
morphology between children with obesity using PAP therapy and children with obesity
not using PAP therapy. Pediatric OSA is a multifactorial disease and craniofacial
morphology is not the only factor contributing to the disease process. Thus if a health
professional notices signs and symptoms of sleep-disordered breathing, the patient should
be referred to a sleep medicine specialist to properly diagnose by PSG, and not rely solely
on craniofacial abnormalities, or sleep questionnaires as diagnostic procedures.
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Appendices
Appendix A: Spruyt and Gozal Sleep Questionnaire107
Last Name: _________________________ First Name : ______________________________
Gender: F ! M ! Date of birth : Month ____ Day ____ Year ____ Age : ______
Over the last 6 months: Please mark each of the following items.
Never Rare
(1 night/week)
Occasional
(2 nights/week)
Frequent
(3 to 4 nights/week)
Almost Always
(more than 4 nights/week)
1 – Do you ever shake your child to make him/her breathe again when asleep? ! ! ! ! !
2 – Does your child stop breathing during sleep? ! ! ! ! !
3 – Does your child struggle to breathe while asleep? ! ! ! ! !
4 – Are you ever concerned about your child's breathing? ! ! ! ! !
Hardly noticeable Moderately strong Strong Very Strong Extremely Strong
5 – How loud is your child snore? ! ! ! ! !
Never Rare
(1 night/week)
Occasional
(2 nights/week)
Frequent
(3 to 4 nights/week)
Almost Always
(more than 4 nights/week)
6 – How often does your child snore? ! ! ! ! !
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Appendix B: Pediatric Sleep Questionnaire108
PEDIATRIC SLEEP QUESTIONNAIRE Version 070424 Child’s Name: , . (Last) (First) (M.I.) Name of Person Answering Questions: . Relation to Child: . Your phone number, days: , and evenings: . Area Code Number Area Code Number
Relative’s name and number in case we cannot reach you: ___________________. __________. Area Code Number
Instructions: Please answer the questions on the following pages regarding the behavior of your child during sleep and wakefulness. The questions apply to how your child acts in general, not necessarily during the past few days since these may not have been typical if your child has not been well. If you are not sure how to answer any question, please feel free to ask your husband or wife, child, or physician for help. You should circle the correct response or print your answers neatly in the space provided. A “Y” means “yes,” “N” means “no,” and “DK” means “don’t know.” When you see the word “usually” it means “more than half the time” or “on more than half the nights.”
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GENERAL INFORMATION ABOUT YOUR CHILD: Office
use only GI1
Today’s Date: . Month Day Year
GI2
Where are you completing this questionnaire? _____________.
GI3
Date of Child’s Birth: .
Month Day Year
GI4
Sex: Male or Female? ______________.
GI5
Current Height (feet/inches) : .
GI6
Current Weight (pounds) : .
GI7
Grade in school (if applicable):____________.
GI8
Racial/Ethnic Background of your Child (please circle): 1.) American Indian 2.) Asian-American 3.) African-American 4.) Hispanic 5.) White/not Hispanic 6.) Other or unknown
GI9
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A. Nighttime and sleep behavior: WHILE SLEEPING, DOES YOUR CHILD …
Office use only
… ever snore?
Y N DK A1
… snore more than half the time?
Y N DK A2
… always snore?
Y N DK A3
… snore loudly?
Y N DK A4
… have “heavy” or loud breathing?
Y N DK A5
… have trouble breathing, or struggle to breathe? HAVE YOU EVER …
Y N DK A6
… seen your child stop breathing during the night? If so, please describe what has happened:
Y N DK A7
… been concerned about your child’s breathing during sleep?
Y N DK A8
… had to shake your sleeping child to get him or her to breathe, or wake up and breathe?
Y N DK A9
… seen your child wake up with a snorting sound? DOES YOUR CHILD …
Y N DK A11
… have restless sleep?
Y N DK A12
… describe restlessness of the legs when in bed? … have “growing pains” (unexplained leg pains)? … have “growing pains” that are worst in bed? WHILE YOUR CHILD SLEEPS, HAVE YOU SEEN …
Y N DK Y N DK Y N DK
A13 A13a A13b
… brief kicks of one leg or both legs? … repeated kicks or jerks of the legs at regular intervals (i.e., about every 20 to 40 seconds)? AT NIGHT, DOES YOUR CHILD USUALLY …
Y N DK Y N DK
A14 A14a
… become sweaty, or do the pajamas usually become wet with perspiration?
Y N DK A15
… get out of bed (for any reason)?
Y N DK A16
… get out of bed to urinate? If so, how many times each night, on average?
Y N DK _______ times
A17 A17a
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Does your child usually sleep with the mouth open?
Y N DK A21
Is your child’s nose usually congested or “stuffed” at night?
Y N DK A22
Do any allergies affect your child’s ability to breathe through the nose? DOES YOUR CHILD …
Y N DK A23
… tend to breathe through the mouth during the day?
Y N DK A24
… have a dry mouth on waking up in the morning?
Y N DK A25
… complain of an upset stomach at night?
Y N DK A27
… get a burning feeling in the throat at night?
Y N DK A29
… grind his or her teeth at night?
Y N DK A30
… occasionally wet the bed?
Y N DK A32
Has your child ever walked during sleep (“sleep walking”)?
Y N DK A33
Have you ever heard your child talk during sleep (“sleep talking”)?
Y N DK A34
Does your child have nightmares once a week or more on average?
Y N DK A35
Has your child ever woken up screaming during the night?
Y N DK A36
Has your child ever been moving or behaving, at night, in a way that made you think your child was neither completely awake nor asleep? If so, please describe what has happened:
Y N DK A37
Does your child have difficulty falling asleep at night?
Y N DK A40
How long does it take your child to fall asleep at night? (a guess is O.K.)
________ minutes
A41
At bedtime does your child usually have difficult “routines” or “rituals,” argue a lot, or otherwise behave badly?
Y N DK A42
DOES YOUR CHILD … … bang his or her head or rock his or her body when going to sleep?
Y N DK A43
… wake up more than twice a night on average?
Y N DK A44
… have trouble falling back asleep if he or she wakes up at night?
Y N DK A45
… wake up early in the morning and have difficulty going back to sleep?
Y N DK A46
Does the time at which your child goes to bed change a lot from day to day?
Y N DK A47
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Does the time at which your child gets up from bed change a lot from day to day? WHAT TIME DOES YOUR CHILD USUALLY …
Y N DK A48
… go to bed during the week?
A49
… go to bed on the weekend or vacation?
A50
… get out of bed on weekday mornings?
A51
… get out of bed on weekend or vacation mornings?
A52
B. Daytime behavior and other possible problems: DOES YOUR CHILD …
Office Use Only
… wake up feeling unrefreshed in the morning?
Y N DK B1
… have a problem with sleepiness during the day?
Y N DK B2
… complain that he or she feels sleepy during the day?
Y N DK B3
Has a teacher or other supervisor commented that your child appears sleepy during the day?
Y N DK B4
Does your child usually take a nap during the day?
Y N DK B5
Is it hard to wake your child up in the morning?
Y N DK B6
Does your child wake up with headaches in the morning?
Y N DK B7
Does your child get a headache at least once a month, on average?
Y N DK B8
Did your child stop growing at a normal rate at any time since birth? If so, please describe what happened:
Y N DK B9
Does your child still have tonsils? If not, when and why were they removed?: HAS YOUR CHILD EVER …
Y N DK B10
… had a condition causing difficulty with breathing? If so, please describe:
Y N DK B11
… had surgery? If so, did any difficulties with breathing occur before, during, or after surgery?
Y N DK Y N DK
B12
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B12a
… become suddenly weak in the legs, or anywhere else, after laughing or being surprised by something?
Y N DK B13
… felt unable to move for a short period, in bed, though awake and able to look around?
Y N DK B15
Has your child felt an irresistible urge to take a nap at times, forcing him or her to stop what he or she is doing in order to sleep?
Y N DK B16
Has your child ever sensed that he or she was dreaming (seeing images or hearing sounds) while still awake?
Y N DK B17
Does your child drink caffeinated beverages on a typical day (cola, tea, coffee)? If so, how many cups or cans per day?
Y N DK _______ cups
B18 B18a
Does your child use any recreational drugs? If so, which ones and how often?:
Y N DK B19
Does your child use cigarettes, smokeless tobacco, snuff, or other tobacco products? If so, which ones and how often?:
Y N DK B20
Is your child overweight? If so, at what age did this first develop?
Y N DK _______ years
B22 B22a
Has a doctor ever told you that your child has a high-arched palate (roof of the mouth)?
Y N DK B23
Has your child ever taken Ritalin (methylphenidate) for behavioral problems?
Y N DK B24
Has a health professional ever said that your child has attention-deficit disorder (ADD) or attention-deficit/hyperactivity disorder (ADHD)?
Y N DK B25
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C. Other Information 1. If you are currently at a clinic with your child to see a physician, what is the problem that brought you? 2. If your child has long-term medical problems, please list the three you think are most significant. _____. . . 3. Please list any medications your child currently takes: Medicine Size (mg) or amount per dose Taken when? __________ ___________________________ ____________ Effect: . __________ ___________________________ ____________ Effect: . __________ ___________________________ ____________ Effect: . __________ ___________________________ ____________ Effect: .
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4. Please list any medication your child has taken in the past if the purpose of the medication was to improve his or her behavior, attention, or sleep: Medicine Size (mg) or amount per dose Taken how often? Dates Taken __________ __________________________ ________________ __________ Effect: . __________ __________________________ ________________ __________ Effect: . __________ __________________________ ________________ __________ Effect: . __________ __________________________ ________________ __________ Effect: . 5. Please list any sleep disorders diagnosed or suspected by a physician in your child. For each problem, please list the date it started and whether or not it is still present. Please list any psychological, psychiatric, emotional, or behavioral problems diagnosed or suspected by a physician in your child. For each problem, please list the date it started and whether or not it is still present.
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7. Please list any sleep or behavior disorders diagnosed or suspected in your child’s brothers, sisters, or parents: Relative Condition ____________________ ________________________ ____________________ ________________________ ____________________ ________________________ D. Additional Comments: Please use the space below to print any additional comments you feel are important. Please also use this space to describe details regarding any of the above questions. Instructions: Please indicate, by checking the appropriate box, how much each statement* applies to this child:
This child often…
Does not apply 0
Applies just a little 1
Applies quite a bit 2
Definitely applies most of the time 3
… does not seem to listen when spoken to directly.
… has difficulty organizing tasks and activities.
… is easily distracted by extraneous stimuli.
… fidgets with hands or feet or squirms i
… is “on the go” or often acts as if “driven by a motor”.
… interrupts or intrudes on others (e.g., butts into conversations or games.
* Derived from DSM-IV.
THANK YOU
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Appendix C Pediatric Polysomnogram Set up
Page 72
Appendix D Pediatric Polysomnogram Data Recording
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73
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