48 volume 2 • issue 1 January / March 2012 •

AbstractThe main iatrogenic effects associated with orthodon-

tic treatment refer to: influence of orthodontic rings onthe periodontal tissue; gum retractions; the effect of theorthodontic treatment on dental root (root resorption);the effect of the orthodontic treatment on alveolar boneheight; mobility and pain associated with orthodontictreatment.

AIM of the study: To assess the degree of rootresorption of incisors, after orthodontic treatment, on agroup of 48 adults with dental-maxillary abnormalities.

Materials and method: The study included 48 youngadult patients, 35 women and 13 men aged 18 to 30 years,who had received fixed orthodontic treatment. To assessthe degree of root resorption (changes at root level andapical contour length), apical radiographies were takenin the maxillary incisors and jaw both at the beginningand end of the orthodontic treatment.

Results: Out of the 239 incisors examined at the be-ginning of orthodontic treatment, 163 showed code 0,meaning 88.1%, and 50 showed a slight squash apex(code 1), respectively 10.9%. Only 1% of all incisors as-sessed presented mild and severe root resorption.

Conclusions: The results of the study show that,generally, an adult orthodontic treatment, applied forfunctional and aesthetic objectives, may have clinicallyacceptable iatrogenic effects.

Keywords: orthodontic treatment, incisor, root resorption

INTRODUCTION

Making a treatment plan for an adult patientis often a challenge for the orthodontist because,even if adults are more compliant, they oftenhave periodontal problems, teeth with abrasion/ attrition restorations well / poorly made, miss-ing teeth, different spacing and other periodon-tal and restorative deficiencies, which maycompromise the final result of the treatment[1-4]. Therefore, currently, the number of adultpatients seeking for orthodontic treatment is in-creasing. In some cases, 30 to 40% of the patientshave ages over 25 years.

Besides, the prophylactic actions of the ortho-dontic treatment for periodontal problemsshould not leave aside its opposite side, namelythe iatrogenic action of this therapy on the peri-odontal tissue [5-10]. The main iatrogenic effectsassociated with orthodontic treatment are: theinfluence of the orthodontic rings on the peri-odontal tissue; gum retraction; the effect oforthodontic treatment on dental root (rootresorption); the effect of orthodontic treatmenton alveolar bone height; mobility and pain asso-ciated with orthodontic treatment [8-10].

AIM OF THE STUDY

To assess the degree of root resorption of inci-sors after orthodontic treatment on a group of48 adults with dental-maxillary abnormalities.

MATERIALS AND METHOD

The study group, including 48 young adultpatients (35 women and 13 men, aged 18 to 30years), received fixed orthodontic treatment, ac-cording to the following criteria:

• Minimum age of 18 years when beginningthe orthodontic treatment;

• Lack of dental and periodontal diseases atthe beginning of the orthodontic treatment;

• Lack of maxilla-facial trauma within his-tory;

• Acceptance of orthodontic treatment withfixed appliances, straight-wire techniquefor a period of 12 -24 months, with an aver-age of 19 months.

In the group of 48 patients, dental-maxillaryabnormalities were evidenced, as follows:

ASSESSMENT OF ROOT RESORPTION DEGREE OF INCISORS AFTERORTHODONTIC TREATMENT IN ADULTS

I. Luchian¹, Catalina Danila², Ioana Rudnic², Silvia Mâr]u³

1. PhD Student, Dept of Periodontology, Faculty of Medical Dentistry “Gr. T. Popa” U.M.Ph., Ia[i2. Assist. Prof. PhD, Dept of Periodontology, Faculty of Medical Dentistry “Gr. T. Popa” U.M.Ph., Ia[i3. Prof. PhD., Dept of Periodontology, Faculty of Medical Dentistry “Gr. T. Popa” U.M.Ph., Ia[iCorresponding author: Silvia Martu parodontologie1@yahoo.com

Orthodontics

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International Journal of Medical Dentistry 49

25 patients – Class I Angle, 11 patients – Class II/ 1 Angle, 10 patients – Class II / 2 Angle,2 patients – Angle Class III classification, respec-tively.

A total number of 40 patients were treatedafter extractions for orthodontic purposes, as fol-lows: 4 extractions of first premolars were madein 4 patients, of upper second premolars in20 patients, and of 2 upper first premolars and1 incisor lower central at 6 patients, of the lowercentral incisor in 5 patients, other combinationsof extractions in 5 patients. 48 patients sufferedno extractions for orthodontic purposes.

Fig. 1. Clinical aspect of orthodontictreatment application

Teeth that had received previous endodontaltreatment were excluded from the study.

To assess the degree of root resorption(changes of root length and of apical contour),apical radiographs were made, at the beginningand end of the orthodontic treatment, to the up-per and lower incisors.

The degree of root resorption was assessedfor each incisor in part, based on the classifica-tion of Kalley and Philips (1991), using the fol-lowing codes:

Code 0 –no root resorption;Code 1 – easy changes on the radiological

apex;Code 2 – moderate resorption, affecting less

than one quarter of root length;Code 3 – severe resorption, exceeding a quar-

ter of root length.

Table 1Degree of root resorption

Pre-treatment code Aftercare code 0 1 2 3 0 1 2 3

Number of lateral upper incisors –158

133 19 4 2 55 80 18 5

RESULTS

The severity degree of root resorption wasevaluated at the beginning and end of the ortho-dontic treatment in the central and lateral, upperand lower incisors.

The data listed in the tables evidence theemergence of fourth apical root resorption afterorthodontic treatment and, in particular, theslight bluntness of the root apex.

Severe resorptions, interesting more than aquarter of roots’ length, have a low incidence.

Tables 2 and 3

Degree of resorption Pre-treatment code Aftercare code 0 1 2 3 0 1 2 3

Number of central upper incisors –166

123 43 0 0 50 81 33 2

Degree of root resorption

Pretreatment code Aftercare code 0 1 2 3 0 1 2 3

Number of central upper incisors – 155

150 5 0 0 68 72 15 0

Fig. 2. Radiological aspects assessing the degree of root resorption before andduring application of orthodontic treatments

ASSESSMENT OF ROOT RESORPTION DEGREE OF INCISORS AFTER ORTHODONTIC TREATMENT IN ADULTS

50 volume 2 • issue 1 January / March 2012 •

Table 4

Degree of root resorption Pre-treatment code Aftercare code 0 1 2 3 0 1 2 3

Number of central upper incisors – 160

157 3 0 0 62 78 18 2

The here presented investigation involvedexamination of:

• 66 maxillary central incisors;• 58 maxillary lateral incisors, the remaining

8 of the total of 166 showing root fillings,being not included in the study;

• 55 lower central incisors, the remaining11 of the total of 166 having been extractedfor orthodontic purposes;

• 60 lower lateral incisors, 6 out of the totalnumber of 166, presenting root fillings,having not been included in the study.

Out of all 239 incisors assessed at the begin-ning of the orthodontic treatment, 163 showedcode 0, i.e. 88.1%, and 50 showed a slight squashapex (code 1), i.e. 10.9%.

Only 1% of all incisors examined showed mildand severe root resorption (codes 2 and 3).

The data listed in the tables indicate that theroot length of incisors is subjected to changesduring orthodontic treatment, as evidenced bychanging of the value code “0” into “1”. After-care code 1 occurs in 48.6% of all incisors exam-ined (out of a total of 311), and code 2 – in 13.3%.

Fig. 3. Severe root resorption of more thanone third of root length

Absence of root resorption was recorded in135 incisors, which means a rate of 36.7%.

Severe root resorption occurred only in 9 inci-sors, i.e. 1.4% of the total 639 examined incisors.

DISCUSSION

The present study confirms that the upper in-cisors are the most susceptible ones to rootresorption,which agrees with other literaturedata [7,10-14]. The incidence and severity of rootresorption registered in other studies are quitedifficult to be compared, as different techniquesand methods had been employed [2,3,16,17]. Thepercents recorded in the present investigationare of 1% for incisors with mild and severeresorption prior to orthodontic treatment, and of14.7% (13.3 and 1.4%), respectively, at the end oftreatment, for the same indices. Only 9 of thetotal number of 639 incisors evaluated at the endof the care treatment showed degree 3 for rootresorption (more than a quarter of root length).11 of the patients in the study required extrac-tion of the lower central incisor for orthodonticpurposes; assessment – by apical X-rays – of theremaining lower incisors at the end of the fixedorthodontic treatment showed code 0 for mostof tooth root resorption.

Root resorption associated with orthodontictreatment is a phenomenon often encountered,yet local mechanisms for preventing this processare available [5,6,14,15]. The root structure fac-tors which may prevent resorption are repre-sented by:

• Anti-angiogenic properties of cement (in-hibition of blood vessels by adjacent ce-ment formation and limiting the access ofosteoclastes involved in resorption);

• Denser insertion of periodontal fibers in ce-ment versus the alveolar bone, which redu-ces the access of osteoclastes to the cementlayer;

• High hardness of cement and its high de-gree of mineralization;

• Cement repair through a tissue whose com-position intermediates the bone-cementstructure [14-19].

Out of the 239 examined incisors at the begin-ning of the orthodontic treatment, 163 showedcode 0, i.e. 88.1%, and 50, i.e. 10.9%, showed aslight squash apex (code 1). Only 1% of all exam-ined incisors showed mild and severe rootresorption (codes 2 and 3).

I. Luchian, Catalina Danila, Ioana Rudnic, Silvia Mâr]u

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International Journal of Medical Dentistry 51

The absence of root resorption of incisors wasrecorded for 135 teeth, which represents a rate of36.7%.

Severe root resorption occurred only in 9 inci-sors, i.e. 1.4% of the total number of 639 exam-ined incisors.

CONCLUSIONS

Root resorption is a plural-factorial phenom-enon that primarily affects the upper and lateralincisors, and also the teeth with propensity toform specific root.

The results of the study show that, generally,an adult orthodontic treatment, applied for func-tional and aesthetic objectives, may have clini-cally acceptable iatrogenic effects.

Radiological examination usually revealsdistal and medial resorptive defects and not ves-tibular and oral ones.

In the absence of plaque and by the applica-tion of physiological orthodontic forces, no asso-ciated iatrogenic effects occur.

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ASSESSMENT OF ROOT RESORPTION DEGREE OF INCISORS AFTER ORTHODONTIC TREATMENT IN ADULTS