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Orthodontics Management of root resorption

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Orthodontics Management of root resorption

Supervisor prof : Maher fouda

By:Ameen mohammed qulah

Root resorption is a pathological process that causes a shortening of the dental root. Root resorption relating to orthodontics is external apical root resorption .

. It is a common consequence and side effect of orthodontic movement. It is found that there are several predisposing factors, therefore an evaluation of these factors should be done by careful examination of personal medical history, dental health, habits and genetics

In orthodontics, induced inflammatory root resorption is a form of pathologic root resorption related to the removal of hyalinized areas of the periodontal ligament following the application of orthodontic forces and is considered an undesirable but unavoidable iatrogenic consequence of orthodontic treatment .

However, as the process of root resorption during orthodontic treatment is usually smooth and ends when the force is removed .

CLASSIFICATION OF ROOT RESORPTION ACCORDING TO TYPE Physiologic root resorption occurring on deciduous teeth during eruption of permanent teeth Pathologic root resorption occurring on permanent roots ACCORDING TO LOCATION Internal root resorption , External root resorption.

Surface resorption occurs commonly periapically as micro defects on the root surface and stops when the instigating agent is removed and there is repair of cementum.Inflammatory resorption Occurs when root resorption progresses into the dentinal tubules to reach the pulpal tissue. Replacement resorption Produces ankylosis of a tooth because bone replaces the resorbed bone substance. inflammation -> osteoclastic activity -> fusion between bone and root surface

ACCORDING TO SEVERITY

Orthodontic tooth movement is based on force-induced periodontal ligament and alveolar bone remodeling (Abuabara, 2007). So, orthodontic forces represent a physical agent capable of inducing inflammatory reaction in the periodontium (Giannopoulou et al., 2008).2-How root resorption begins?

When a tooth moves, a necrosis of periodontal ligament on the pressure side with formation of a cell-free hyaline zone occurs..

This event is followed by osteoclast resorption of the neighbouring alveolar bone and bone apposition by osteoblasts on the tension side (Abuabara, 2007). The resorption process of dental hard tissues seems to be triggered by the activity of some cytokines as well as that of bone. Immune cells migrate out of the capillaries in the periodontal ligament and interact with locally residing cells by elaborating a large array of signal molecules (Jger et al., 2005)According Consolaro et al. (2011), the causes of root resorption should be related to the loss of root surface cementoblasts

Determining the cause of root resorption requires a thorough history, rescuing the previous dental history, addiction, accidentes, previous treatment, associated diseases and other details relevant to pathogenesis, but not always remembered by patients and identified by orthodontists3. Etiology of root resorption

Several authors have pointed out that the multifactor etiology of root resorption is complex, but the condition appears to result from a combination of individual biologic variability, genetic predisposition and the effect of mechanical factors (Bartley et al., 2011; Weltman et al., 2010; Zahrowski & Jeske, 2011).

PHYSIOLOGIC PATHOLOGIC : LOCAL CAUSES, SYSTEMIC Dental trauma, Herpes Zoster infection Cysts Pagets disease Tumours Hormonal imbalance: Excessive Mechanical Forces HypophosphataemiaImpacted teeth HypothyroidismIntracoronal Bleaching Hypopituitarism Hyperpituitarism Hyperparathyroidism Etiology of Root resorptions

Orthodontic treatment-related factors

The ideal force for tooth movement would mimic a physiologic balance between tooth movement and bony adaptation The optimal force level for tooth movement between 7 and 26 g per square centimeter. When force exceeded this threshold, root resorption occursOrthodontic treatment-related factors

When pressure decreases below this limit, root resorption ceases (Owman Moll et al., 1996). King and Fischlschweiger (1982), find that light forces produced insignicant root resorption, whereas intermediate or heavy forces resulted in substantial crater formation

In this context, several aspects have been related to induce root resorption during orthodontic treatment. This aspects are as follows: Treatment duration Magnitude of the applied forces Direction of tooth movement Amount of apical displacementForce application method (continuous vs. intermittent) Type of applianceTreatment technique

In a study, Acar et al. (1999) compared a 100-g force with elastics in either an interrupted (12 hours per day) or a continuous (24 hours per day) application. Group who has teeth experiencing orthodontic movement had signicantly more root resorption than the control group. Besides that, continuous force produced signicantly more root resorption than discontinuous force application. Treatment duration, force application method and magnitude of the applied forces

Orthodontic force leads to micro trauma of periodontal ligaments and activation of inflammation related cells . According to some researches there was no root resorption difference detected while using low and high forces (50 g and 200 g).According to Schwartz,forces increasing 20-26 g/cm 2 , cause periodontal ischemia, which may lead to root resorption . When orthodontic force decreases to less than 20-26 g/cm 2 tooth root resorption stops.Orthodontic force

Optimal force for orthodontic tooth movement but not causing root resorption should be 7-26 g/cm 2 on root surface area. It was established that intermittent force causes root resorption more rarely than the continuous force because the intermittent force protects from formation of hyalinized areas or it allows reorganization of hyalinized periodontal ligaments and restoration of blood circulation at the time, when forces are not active. Continuous force leaves no time to repair of damaged blood vessels and other periodontal tissues and this may lead to higher level of root resorption

Most studies agree that the risk and severity of external apical root resorption increases as the duration of orthodontic treatment increases. Sameshima and Sinclair looked at a sample of 868 patients collected from 6 different specialist practitioners and found longer treatment times to be significantly associated with increased root resorption for maxillary central incisors. The reasons for the longer duration in treatment may also have had an influence on the increased levels of root resorption seen in these patients. Duration

Evaluating the direction of tooth movement (intrusive vs. extrusive force), Han et al. (2005) found that root resorption from extrusive force was not signicantly different from the control group. Intrusive force signicantly increased the percentage of resorbed root area . Direction of tooth movement

In orthodontics, total apical displacement might represent a better marker for overall treatment activation. A tooth that is moved greater distances through bone is subjected to longer durations of activation. There is no way to move a tooth between two points with xed appliances, without causing hyalinization. In 2005, Fox also found that treatment-related root resorption is correlated with the distance the apex moves and the length of time the treatment took. Amount of apical displacement

Mandall et al. (2006) compared 3 orthodontic archwire sequences in terms of: (1) patient discomfort(2) root resorption, and (3) time to working archwire. In that study, all patients were treated with maxillary and mandibular preadjusted edgewise appliances (0.022-in slot), and all archwires were manufactured by the same manufacturer. The results showed that there was no statistically signicant difference between archwire sequences, for maxillary left central incisor root resorption Archwire sequence

Root resorption most often occurs in the apical part of the root, because forces are concentrated at the root apex because orthodontic tooth movement is never entirely translatory and the fulcrum is usually occlusal to the apical part of the root; periodontal ligaments are situated in different directions in the apical part of the tooth rootTooth structure.(Biological factors)

Fixed appliances have been shown to cause more root resorption than removable appliances which can be explained by the increased range of tooth movement afforded by fixed appliances .

The risk of root resorption associated with different bracket designs has Yielded In conclusive resultsType of appliance

Brin et al. (2003) examined the effect of 2-phase vs 1-phase Class II treatment on the incidence and severity of root resorption. The results showed that children treated in 2 phases with a bionator followed by xed appliances had the fewest incisors with moderate to severe root resorption, whereas children treated in 1 phase with xed appliances had the most resorption. However, the difference was not statistically signicant.

Treatment technique

Linge suggested that the use of inter maxillary elastics increased the amount of root resorption but Sameshima and Sinclair did not find any correlation. No difference has been found between the use of sectional and continuous mechanics. It is generally agreed that the use of rapid maxillary expanders is associated with increased levels of root resorption.Treatment Mechanics

Possible a previous history of root resorption Tooth/root morphology, length and roots with developmental abnormalitiesGenetic influences , systemic factors, including drugs hormone deficiency, hypothyroidism , asthma, proximity of root to cortical bone , alveolar bone density, Previous Trauma, endodontic treatment , severity and type of malocclusion patient age Patient-related risk factors

Nishioka et al. (2006) determined whether there is an association between excessive root resorption and immune system factors. The prevalence of root resorption found was 10.3%. Allergy, abnormalities in root morphology and asthma showed be high risk factors for the development of excessive root resorption during orthodontic tooth movement.Systemic factors

Some teeth are more susceptible to root resorption, other less. According to the research data teeth of the maxillary teeth are more sensitive to root resorption than the mandibular teeth and anterior teeth are more susceptible to root resorption relative to posterior teeth . Maxillary incisors are the teeth most affected by root resorption, because the degree of root resorption is correlated with the distance of the apex of an incisor moves and the length of time of the orthodontic treatment . Other researches have shown that root resorption is more common in mandibular incisors Specific tooth vulnerability to root resorption.

Case report 25-year-old male patient sought orthodontic treatment after being subjected to a four-year therapy, as revealed by . Although he had most roots with severe resorption No teeth should have been extracted or submitted to endodontic procedures. Nevertheless, three maxillary incisors underwent endodontic treatment which, in fact, does not affect root prognosis.

Dental pulp does not influence external resorption Similarly, intracanal dressing does not interfere in the cause of resorptive processes while active forces remain

after four years of orthodontic treatment. Apparently, teeth have no bone or alveolar cortical bone support; however, periapical radiograph reveals detailed root and bone structures involved in the resorption process.

Severe inflammatory root resorption revealed by 3Dtomographic scans that allow a contextual and comparative as-sessment of the process in each tooth and thei respective surfaces

During the first appointment, after four years of previous orthodontic treatment, patients teeth did not show increased mobility. Occlusion assessment revealed absence of incisal guidance and Class III relationship between canines and molars

As stated by the patient, there was an ongoing attempt to correct Class III by means of elastics: Intermittent forces such as those exerted by intermaxillary elastics might favor root resorption during orthodontic treatment. Considering the severity of root resorption and the conditions of remnant cervical root (responsible for 60% of periodontal support)

Procedures must be followed:

1 st - Teeth can remain in function and esthetics for an indefinite period of time without endodontic treatment, except for cases in which endodontic therapy is exclusively required.2 nd - Occlusion must be thoroughly balanced without further interference. Should there be any type of interference they must be immediately corrected.3 rd- The patient should be advised to use a mouthpiece while practicing sports. In the event of a trauma occurs, clinicians should follow the same procedure employed for teeth without root shortening.

4 th - Making patients aware that while eating, they should avoid grasping hard food, such as some fruit or bread, with their teeth, only. 5 th - In cases of bruxism, even if mild and occasional, the patient should ideally, routinely and methodically use individual acrylic plates while sleeping.6 th - Since roots are too short, tooth movement should be avoided.7 th - Should movement be exclusively orthopedic without involving compromised teeth and their anchorage, the periodontal ligament is not affected by inflammation or stress. In other words, orthopedic movement does not induce a new cycle of root resorption.

8 th - Chronic inflammatory periodontal disease associated with dental plaque must be prevented by properly advising the patient about oral hygiene. Minor cervical bone loss is utterly significant. 9 th - Fully or partially unerupted teeth must be extracted, especially if they are too near other teeth which might not only lead to root resorption, but also hinder the case due to orthodontic reasons.10 th - Parafunctional habits, such as onychophagia, object grasping with teeth, labial or lingual piercings, must be corrected and avoided

This case a 20-year-old female with the chief complaint of maxillary protruding and irregularly aligned mandibular anterior teeth. Her medical history showed no allergies or medical problems. The overbite was +3.0 mm, and the overjet +3.0 mm. After extraction of the four rst premolars, a multi-bracket treatment was started.. case report

A severe root resorption of the maxillary anterior teeth was found 12 months after active treatment. The maxillaryanterior segmental osteotomy was chosen as the compensatory treatment. The total treatment period was 2 years and 7 months.The post-retention panoramic radiograph showed no developmental root resorption

. Treatment planWe established the treatment plan under consideration to the soft tissue facial prole. The treatment plan wasdetermined as follows: (1) Extraction of upper and lower rst premolars; (2) Alignment of upper and lower incisors with standard edgewise appliances and (3) Retention to achieve stabilization of the improved tooth alignment and facial esthetics.

Treatment progressAfter extraction of the four rst premolars and mandibular leftthird molar, leveling and alignment of teeth were initiatedwith a standard edgewise appliance (0.018 in. 0.025 in.).After 4 months alignment of the maxillary anterior teeth,each of the maxillary canines was retracted by pre-stretchedelastics using a same round wire (0.016 in. CoCr alloy). Themaxillary canine retraction and en masse retraction of themandibular arch were almost nished after 12 months ofactive treatment (Figs. 1 and 2B).

A periapical radiograph and panoramic radiograph were taken to check the maxillary incisor roots. A severe root resorption of maxillary central and lateral incisors was found . Various treatment plans, stop treatment or decrease the treatmentperiod, take resting and restart the treatment using lower forces, and maxillary anterior segmental osteotomy to retract maxillary anterior teeth, were discussed with the patient. She chose the last one, then the wassmund technique foranterior maxillary segmental osteotomy was performed.

The maxillary incisors were set backward 5 mm and upward 3 mm, respectively, to improve maxillary protrusion. The maxillo-mandibular xation was employed for 14 days. Rigid xation was employed using two titanium mini-plates in maxillary. Seven months after surgery, all bands and brackets were removed. Total treatment period was 2 years and 7 months. The maxillary peg-shaped lateral incisors pose esthetic problems and restored with resin.

The post-retention panoramic and periapical radiograph showed no developmental root resorption and periodontal bone loss (Figs.3E and 4D). There were no periodontal pathological signs, andthe patient was symptom-free. The patient was satised withthe results of treatment.

CLINICAL CASE REPORT A 17-year-old female patient whose chief complaint was the presence of diastemas in the maxillary anterior region, an esthetic and psychological concern that she described inhibited and limited her interaction with other people, presented for treatment. She was also con-cerned about the potential risk of losing some of her teeth due to general root resorption which had been previously diagnosed by another orthodontist who had refused to treat her due to the potential risks involved in trying to close the spaces.

The patient presented a straight profile, good health condition and oral hygiene, normal breathing pattern and atypical swallowing pattern (Fig 1). Intraoral examination revealed Class I malocclusion, 2-mm overjet and 5% overbite, coinciding dental midlines, moderate spacing in both arches and upper and lower labialized and protruded incisors (Figs 1 and 2)

Radiographic analysis Revealed the presence of all teeth which exhibited altered crown-root proportion, (maxillary right permanent lateral incisor, mandibular right first and second premolars) with thinned and short roots, sclerosis of root canals and complete root resorption of maxillary permanent left lateral incisor. Tooth buds of maxillary and mandibular left third molars at Nolla Stage 6 development were observed, as well as the presence of mandibular second primary molar with congenital absence of mandibular left second premolar and mandibular right third molar (Fig 3)

TREATMENT OBJECTIVES The aim of orthodontic treatment was mainly to meet patients esthetic expectations, achieve closure of anterior diastemas with light forces and also maintenance of crown-root proportion.TREATMENT ALTERNATIVESTreatment options for this patient were limited due to her dental characteristics and malocclusion. At first orthodontic treatment was not an option, but the patient was highly concerned about esthetics. Another option was not using Orthodontics to fully close diastemas between maxillary teeth, but distributing those spaces to be restored with composites instead, so as to increase mesiodistal width, and also restore with osseointegrated implants the absent premolar and maxillary permanent left lateral incisor. Nevertheless, the patient did not count with the economic resources for this treatment option. Thus, it was decided to start orthodontic treatment focused on fully closing diastemas with light forces. The patient agreed and understood the risks

TREATMENT PROGRESSPrior to treatment onset, the patient was informed about the characteristics of the progressive pulp pathology condition she had and the limitations, risks and objectives of treatmentTreatment plan required initial consultation with an endodontist in order to evaluate the degree and severity of external root resorption and begin orthodontic treatment with minimal risk, while taking into account the existing limitations.Orthodontic treatment initiated first in the upper posterior segments between canines and molars with an edgewise-standard technique. During the first phase of treatment, low caliber NiTi wires were used (Fig 4). Once the posterior segments of the maxillary arch were consolidated, fixed appliances were installed in the upper anterior segment where teeth were more affected by re sorption

Space closure in the lower arch was initiated with a frictional technique using light elastomeric chains. Strict panoramic radiographic control was carried out every eight months based on clinical criteria in order to monitor the progression of pulp pathology (Fig 5). Given the positive response during treatment, the space between mandibular first premolar and molar was closed by attraction with a closed loop which had a tip back bend on the molar in order to protract and disincline it (Fig 4).

TREATMENT RESULTSAfter orthodontic treatment with fixed appliances, the shape and contour of both dental arches improved, the rotations were fixed, diastemas were closed, pro clination of maxillary and mandibular incisors was improved, a better occlusal relationship was achieved, overbite and overjet were corrected, the Curve of Spee was flattened, her nasolabial angle improved and a harmonic smile was achieved (Figs 6, 7 and 8).Panoramic and periapical radiographs taken at the end of treatment revealed that there was no significant progression of root resorption and the periodontal condition was acceptable (Fig 8).

CONCLUSIONS

1) Orthodontic treatment of patients with idiopathic multiple root resorption offering them esthetical and physiological solutions is possible considering that the patient understands potential risks and limitations.2) Orthodontic management is based on simple mechanical techniques that include light and controlled forces, allowing predictable movements which are physiologically acceptable if pulp and periodontal limitations are considered.3) A complete history of patients medical background allows identification of any systemic condition that might be associated with the pulp pathology.4) An informed consent form is indispensable and protects the clinician in case of any legal implication that might arise in these types of cases.

CLINICAL CASE REPORT Female patient, aged 10 years, was referred by her pedodontist for orthodontic treatment. She presented with a slightly convex profile, good maxillomandibular relationship (Fig 3), Class I malocclusion, constricted upper and lower arches (Fig 4), anterior mandibular and maxillary crowding, and mandibular midline shift (1 mm to the right).

Four years earlier, the patient had suffered a fall with total avulsion of the upper central right and extrusion of the upper central right (Fig 2, A). According to her pedodontist, both radiographically and clinically, the teeth had open apices with divergent walls. Left central upper was repositioned and right central upper was re implanted (Fig 2, B). A semi-rigid retainer was bonded and finshing line (nylon) was placed around teeth upper canin right , upper central right , upper central left , upper canin left. Amoxicillin 250 mg was prescribed for 7 days, Cataflan drops for three days, and aqueous polyvinylpyrrolidone for cleaning the region. Liquid and semi-liquid food was recommended

Subsequently, upper central left underwent endodontic treatment with calcium hydroxide for root apexification.At the time of the initial orthodontic examination, upper central left showed signs of resorption , light browning of the crown and a slight step between central upper right and lateral upper left. The central upper right appeared normal both clinically and radiographically (Fig 4, B).

The orthodontic plan provided for the use of a standard Bimler appliance for upper and lower arch expansion and a fixed orthodontic appliance in a second stage for tooth alignment and leveling, and occlusion detailing.After nine months of treatment with the removable appliance, we observed a significant increase in the size of the step between the central upper left and the central and lateral upper right due to the ankylosis in central upper left .We then decided to amputate the crown of central upper left and to bury the intraosseous root

while suspending the use of the removable appliance and mounting a fixed orthodontic appliance, straight wire Roth prescription . A pontic was bonded between cental upper left and lateral upper right and remained in place until the end of the active orthodontic treatment and retention period .

The patient will wait until her growth is completed before having an implant and prosthesis placed in the edentulous area .

The clinicians should have in mind that abnormal root morphology may increase the risk of root resorption. This is specially valid for pipette-shaped roots. Maxillary incisors seem to be the teeth most likely to suffer from EARR. From the root resorption point of view orthodontic treatment should begin as early as possible since there is less risk of root resorption in young and developing teeth.Conclusion

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Light orthodontic forces seem to present a smaller risk of resorption than heavy forces. The use of interrupted forces seems to give less root resoption If initial resorption is detected, a pause in treatment of two-three months should be considered. With sustained quality, treatment duration should always be as short as possible. It is very important that the patient is fully informed that root resorption can be a consequence of his/her orthodontic treatment with fixed appliance. than continuous forces.

In conclusion, amount of root movement and presence of long, narrow, and deviated roots increase the risk for apical root resorption. In addition, use of elastics may be a risk factor for the teeth that support the elastics. A correlation between gender and apical root resorption has been reported, females are more susceptible than males

Treatment with rectangular archwires plus intermaxillary elastics and duration of treatment were significantly related to the severity of root resorptionOnly heavy forces responsible for root resorption, but intensity and duration are also of great importanceResults confirmed hypothesis that type of initial malocclusion may not be of importance for amount of apical root resorption during treatment

Several authors believe that overjet is a powerful predictor for resorption. However, overjet can be corrected in several ways other than moving the roots of maxillary anterior teeth, such as growth adaptation in growing persons, anterior expansion of the mandibular dentition, and orthognathic surgery. Also, appliances may be present for longer periods without creating pressure on the teeth.

Final considerations

Teeth with only the cervical third remaining from orthodontically induced external root resorption must remain in ones mouth with function and esthetics preserved.In these cases, endodontic treatment is not recommended for affected teeth because the pulp is not involved in the process and the post-treatment phase of endodontic therapy might be a complicating factor due to risks of accidental contamination or filling material overflow. .

Accurate diagnosis of causes and stages of development, in addition to occlusal trauma control and oral hygiene as well as the use of a mouthpiece to avoid trauma and acrylic plates to correct bruxism are part of the protocol recommended to treat cases of extreme root resorption associated with induced tooth movement. Additionally, care should be taken with regards to reading of imaging exams, since tomography does not accurately reveal minor details of thin cortical bone and trabeculae

Periapical radiograph, on the otherhand, provides precise details, especially in terms of detecting cervical bone and root loss. Should proper care be taken by clinicians and patients, the chances of tooth loss in extreme cases of root resorption associated with induced tooth movement are reduced

Thank you for your attention