Mandibular Molar Distalization Research Articles

Vertical Control in Molar Distalization by Clear Aligners: A Systematic Review and Meta-Analysis.

Background: Molar distalization is used to correct molar relationships or to create space for mild anterior crowding. However, whether clear aligners can provide proper vertical control with the sequential distalization strategy has been highly debated. Thus, the current study aimed to systematically review the amount of dentoskeletal changes in the vertical dimension that results from sequential molar distalization in clear aligner therapy without temporary anchorage devices (TADs). Methods: Registered with PROSPERO (CRD42023447211), relevant original studies were screened from seven databases and supplemented by a manual search by two investigators independently. Articles were screened against inclusion and exclusion criteria, and a risk of bias assessment was conducted for each included article. Relevant data were extracted from the included articles and meta-analysis was performed using RStudio. Results: Eleven articles (nine for maxillary distalization and two for mandibular distalization) were selected for the final review. All studies have a high or medium risk of bias. For maxillary molar distalization, the meta-analysis revealed 0.26 mm [0.23 mm, 0.29 mm] of maxillary first molar intrusion based on post-distalization dental model analysis, as well as 0.50 mm [-0.78 mm, 1.78 mm] of maxillary first molar intrusion and 0.60 mm [-0.42 mm, 1.62 mm] of maxillary second molar intrusion based on post-treatment lateral cephalometric analysis. Skeletally, there was a -0.33° [-0.67°, 0.02°] change in the SN-GoGn angle, -0.23° [-0.30°, 0.75°] change in the SN-MP angle, and 0.09° [-0.83°, 1.01°] change in the PP-GoGn angle based on post-treatment lateral cephalometric analysis. There was insufficient data for meta-analysis for mandibular molar distalization. Conclusions: No significant changes in vertical dimension were observed, both dentally and skeletally, after maxillary molar distalization with a sequential distalization strategy. However, further studies on this topic are needed due to the high risk of bias in the currently available studies.

Boundary of mandibular molar distalization in orthodontic treatment: A systematic review and meta-analysis.

To explore the mandibular retromolar space length (MRSL), initial root-inner cortex contact percentage (IRCCP), and the various factors that influence mandibular molar distalization. Searches were undertaken in PubMed, EMBASE, Web of Science, Cochrane Library, Scopus, and grey literature (Google Scholar and OpenGrey) for eligible cross-sectional observational studies measuring the MRSL and IRCCP in healthy adult patients. The risk of bias and evidence quality were evaluated using the Joanna Briggs Institute's checklist and GRADE framework. Thirteen studies involving 1169 patients were included for qualitative synthesis. Seven of these studies were eligible for quantitative analysis. Meta-analysis showed that the mean MRSL at the subfurcation-6 mm plane in Asian normodivergent cases was 3.78 mm (95% confidence interval [CI]: 2.81-4.35; I2 = 79.7%) for skeletal Class-I malocclusions, 3.02 mm (95% CI: 2.10-3.94; I2 = 62.5%) for Class-II, and 4.43 mm (95% CI: 3.14-5.73; I2 = 75.1%) for Class-III. The mean MRSL at the sub-cementoenamel junction (CEJ)-10 mm plane for Asian, Class-I, normodivergent cases was 3.28 mm (95% CI: 2.44-4.12; I2 = 68.9%). The mean IRCCP for Asian, Class-I, normodivergent cases was 27.2% (95% CI: 0.22-0.32; I2 = 0%). In Asian normodivergent cases, MRSL ranges from 3.28 to 4.43 mm with a 27.2% IRCCP for Class-I. Cone-beam computed tomography imaging is recommended for measuring the MRSL in the apex region particularly before molar distalization. Factors influencing MRSL and IRCCP include different races, skeletal patterns, facial types, and third-molar status.

Effects of different patterns of movement for correcting a deep curve of Spee with clear aligners on the anterior teeth: a finite element analysis

ObjectiveTo analyse the anterior teeth effects of clear aligners on five different patterns of mandibular molar movement and to define the most effective configuration to be implemented with clear aligners through finite element analysis.MethodsA three-dimensional mandibular model with a deep overbite in the mandible was constructed using cone beam computerized tomography (CBCT) data. The model included the mandibular dentition, mandibular periodontal ligaments, attachments, and aligners. Five models were created: (1) configuration A: second molar distalization (0.25 mm); (2) configuration B: second molar distalization (0.25 mm), first molar extrusion (0.15 mm); (3) configuration C: second molar distalization (0.25 mmm), first and second premolar extrusion(0.15 mm); (4) configuration D: second molar distalization (0.25 mm), first molar and first/second premolar extrusion(0.15 mm); and (5) configuration E: second molar distalization (0.25 mm), first molar and first/second premolar extrusion (0.15 mm), first molar and first/second premolar expansion (0.15 mm).ResultsIn all configurations, the anterior teeth exhibited labial tipping and the mandibular central incisor of configuration E showed the highest labial tipping. Configuration E demonstrated a relatively minor impact on mandibular molars distalization compared with configuration A. Configuration A showed the highest distal displacement value, and configuration E produced the lowest displacement value. Configuration E caused the highest periodontal ligament (PDL) pressure of the central and lateral incisors. The differences in the canines between configurations C and D,were not significant, and the stress distribution differed among the five groups.ConclusionsAll patterns utilizing clear aligners facilitated mandibular molar distalization. Extruding the premolars and second molar distalization at the same time had little impact on second molar distalization; When expansion and extrusion were simultaneously performed during the distalization of mandibular molars, our prime consideration was the alveolar bone on the labial side of the anterior teeth to prevent the occurrence of gingival recession, dehiscence, and fenestration. Due to the lack of consideration for periodontal tissues in this study, clinical protocols should be designed based on the periodontal status of the mandibular anterior teeth.

Three-dimensional measurement and analysis of Mandibular Molar Distalization assisted by micro-implant anchorage combined with clear aligner.

To investigate the effect of micro-implant anchorage combined with a clear aligner on the efficiency of mandibular molar distalization and the protection of anterior teeth anchorage, provide reference for clinical scheme design. This is a prospective study. Seventeen patients who were treated in the Orthodontics Department of the Hospital of Stomatology affiliated to Fujian Medical University from 2019 to 2021 and used Invisalign clear aligners to move mandibular molars distally were included and divided into two groups according to anchorage types: Group-A and Group-B. Group-A (ten cases) were treated without micro-implant anchorage, while Group-B (seven cases) were treated with micro-implant anchorage nails for enhanced anchorage. The effect of micro-implant anchorage on crown and root distal movement of mandibular molars and the difference in three-dimensional movement between mandibular molars and mandibular central incisors were analyzed. The crown distalization efficiency of mandibular first and second molars in Group-B was 68.66% and 71.02%, respectively, which were higher than those in Group-A(p<0.05). The mandibular central incisors in Group-A showed labial displacement and a small amount of elongation, while those in Group-B showed less anchorage loss(p<0.05). In Group-A, the crown was tilted in the distal direction and moved in the buccal direction during mandibular molar distalization(p<0.05). While in Group-B, the crown was tilted in the distal directio (p<0.05) and the mandibular second molar was depressed(p<0.05). In the process of mandibular molar distalization assisted by micro-implant anchorage combined with a clear aligner, better protects the anchorage of the mandibular central incisor and improves the efficiency of the molar crown distalization.

Efficacy of Clear Aligners in Treating Class III Malocclusion With Mandibular Molar Distalization: A Systematic Review.

The primary goal of orthodontic therapy in pseudo-class III is to restore the proper dental connection by rectifying the canine and molar relationship to Class I through lower molar and premolar visualization, as well as providing normal anterior overjet. The purpose of this systematic study was to determine the efficacy of clear aligners in treating class III malocclusion with mandibular molar distalization. A wide range of searches were done on various search engines like Cochrane, Web of Science, Embase,PubMed, Scopus, and Google Scholar to collect relevant articles related to our study. This review's article selection was guided by the PRISMA flowchart. The electronic findings provided numerous articles with nearly 78 articles regarding clear aligners in class III malocclusion with molar distalization. From this, seven full-text papers were evaluated for eligibility criteria, with two articles being rejected with justification and five articles being elaborated in the current systematic review. The current evidence of this review suggested that the clear aligners were effective in correcting class III malocclusion with molar distalization. The amount of molar distalization is about 2 to 3 mm, which helps in achieving molar and canine relationship in class I, with a high compliance level and also improvement of the facial profile.

Mandibular Molar Distalization in Class III Malocclusion: A Systematic Review

Class III Malocclusion presents a complex orthodontic challenge with various treatment options, including orthodontic camouflage and orthognathic surgery. Among these, mandibular molar distalization stands as an orthodontic approach for treating Class III Malocclusion in adults. This systematic review aims to evaluate the current evidence regarding mandibular molar distalization techniques in the treatment of Class III. The search across PubMed, Scopus, Cochrane, and Web of Science databases yielded 582 articles, from which eight met the inclusion criteria. These inclusion criteria were as follows: English language, full text, studies randomized clinical trials, and retrospective studies that evaluated various methods of mandibular distalization for Class III Malocclusion in adult patients, from 2013 to May 2023. Lower molar distalization has gained attention as a non-surgical alternative with effective and efficient outcomes. However, various treatment modalities have limitations, including reliance upon malocclusion severity, diagnosis, patient cooperation, and operator experience. From the studies analyzed, it was found that techniques using skeletal anchorage with TADs, mini-plates, or ramal plates, offer stable anchorage and controlled tooth movement, they allow unilateral action in cases of asymmetry, and they are the most effective methods for achieving distal body displacement of the tooth. Despite the promising results, the relatively small number of studies calls for more high-quality research to explore the efficacy and outcomes of different mandibular molar distalization approaches. The lack of standardized protocols and guidelines for mandibular molar distalization in Class III Malocclusion is also attributed to the limited available literature.

Evaluation of bone area in the posterior region for mandibular molar distalization in class I and class III patients

The aim of this study was to investigate the bone area in the posterior region, which is important for mandibular molar distalization in skeletal class I and class III individuals with normodivergent and hyperdivergent vertical growth patterns. In this retrospective study, cone-beam computed tomography(CBCT) scans of 120 individuals divided into 4 groups as class I normodivergent (group-I), class I hyperdivergent (group-II), class III normodivergent (group-III), and class III hyperdivergent (group-IV). Retromolar area at crown level measurements was performed on CBCT-derived panoramic radiographs and axial sections. Retromolar area at the root level was measured 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm apical to cemento-enamel junction at CBCT axial sections. Retromolar area decreased towards the root apex in all groups and smallest retromolar area was level of CEJ10mm in all groups. At any root level, the distal root of the mandibular second molar tooth was in contact with the mandibular inner or outer lingual cortex; 50% in group-I, 46.7% in group-II, 23% in group-III, and 23% in group-IV. In normodivergent individuals, the retromolar area length at the root level is observed to be higher in class III than in class I at almost every level. In hyperdivergent individuals, on the other hand, only at CEJ10mm level, it is higher in length in class III than in class I. Vertical growth pattern has no effect on the root and crown level retromolar area in class I and class III individuals. CBCT provides more useful information than panoramic radiographs for patients who are scheduled for large mandibular molar distalization.

Assessment of mandibular retromolar space in adults with regard to third molar eruption status.

The aim of this study was to compare the difference in length and width of the mandibular retromolar space (RMS) stratified by the different eruption and impaction statuses of the third molars in patients with skeletal Class I malocclusion. The right mandibular RMS in 186 adult patients categorized according to the different statuses of the third molar was analyzed by using cone-beam computed tomography (CBCT). The shortest distances between the inner lingual cortex of the mandibular body and second molar root were measured parallel to the posterior occlusal line (POL) at depths of 2, 4, 6, 8, and 10mm (mandibular retromolar space length in root level, RLin2,4,6,8,10) on the axial slices with the cementoenamel junction (CEJ) as the reference level. The width of the RMS and second molar root was measured vertical to the POL at the terminal point of the molar distalization at depths of 2, 4, 6, 8, and 10mm (width of the mandibular retromolar space, BW2,4,6,8,10/ width of the second molar distal root, TW2,4,6,8,10) from the CEJ. RL in different measurement planes was 2.72 ± 2.22 ~ 3.74 ± 2.26 for Group A, 5.27 ± 1.68 ~ 9.10 ± 2.04 for Group B, 1.94 ± 2.34 ~ 5.71 ± 4.37 for Group C, 1.83 ± 2.95 ~ 5.05 ± 4.24 for Group D, and 5.93 ± 3.97 ~ 10.52 ± 2.16 for Group E. The BW measurement results for A ~ E group were 9.71 ± 1.41 ~ 10.51 ± 1.81, 9.83 ± 1.39 ~ 12.55 ± 2.11, 9.96 ± 1.21 ~ 12.17 ± 1.62, 9.82 ± 1.47 ~ 12.28 ± 2.77, and 10.02 ± 1.20 ~ 12.75 ± 0.82, respectively. There was no significant difference between men and women in any measurements (P > 0.05). Patients with normal third molars erupted and those vertically impacted possessed larger RMS lengths than those in which the third molars were missing, horizontally impacted or mesially impacted (P < 0.05). In each measurement plane, TW was significantly smaller than BW (P < 0.05). Sex had no effect on the length or width of the mandibular RMS. Different statuses of third molars can also differentially affect the mandibular RMS. The mandibular RMS width is not a limit for mandibular molar distalization. When considering the distalization of mandibular molars, more attention should be directed to the lingual cortex of the mandible, and CBCT scans are recommended for patients who require significant mandibular molar distalization. The mandible buccal shelf and retromolar area maybe a safe zone to insert the miniscrew for molar distalization.

Mandibular retromolar space in adults with different sagittal skeletal patterns.

To analyze the mandibular retromolar space among normal-divergent adult patients with different sagittal skeletal patterns by cone-beam computed tomography (CBCT). CBCTs of a total of 120 normal-divergent adult patients were investigated. Patients were categorized into the following three groups according to their ANB angle: skeletal Class I (48 patients), skeletal Class II (36 patients), and skeletal Class III (36 patients). Four different planes parallel to the mandibular occlusal plane were used to measure the retromolar space. The retromolar space was measured by two reference lines and then compared between different sagittal skeletal patterns groups. The incidence of root contact with the inner lingual cortex was compared among the three groups. The retromolar space of the Class III patients was significantly larger than that of Class I patients and Class II patients. Compared with Class I and Class III patients, Class II patients had a smaller retromolar space and higher incidence of contact with the inner cortex of the mandible. Class III patients had a larger retromolar space than Class I patients and Class II patients in four different planes. The mandibular retromolar space should be evaluated by CBCT in patients who need mandibular molar distalization.

Identification of key determinant for predicting feasible mandibular molars distalization

Background/purposeThe distal movement of mandibular molar is effective treatment strategy, while it is still difficult to determine if the posterior available space is sufficient or not for mandibular molar distalization before treatment. Thus, this study aimed to identify the measurement items of lateral cephalograms with the potential to accurately predict the posterior anatomical limit of mandibular molar distalization. Materials and methodsCephalometric images of 26 patients were used. We establish five landmarks: the distal contact point (D7), the distal root apex (R7), the distal tooth cervix (TC) of the mandibular second molar, the anterior border of the ramus (ABR) and the external oblique line of the mandible (E). The D7-ABR and the vertical height between TC and E (TC-V), the distal movements of D7 and R7 during treatment (D7D, R7D) were measured. The subjects were divided into bodily-like and tipping movement group, according to the ratio D7D/R7D. ResultsSignificant differences in D7D and R7D were found between the bodily-like movement and tipping movement groups (P < 0.01). Moreover, TC-V was significantly larger in the bodily-like movement group (P < 0.01). A positive correlation was found between TC-V and D7D (r = 0.68) and between TC-V and R7D (r = 0.69), indicating that TC-V has the potential to make accurate predictions for D7D and R7D. D7-ABR did not show a positive correlation with R7D. ConclusionUsing TC-V can strengthen the prediction of available posterior space for mandibular molar distalization.

Efficacy of mandibular molar distalization by clear aligner treatment.

At present, the research on clear aligner of molar distalization mainly focuses on the upper jaw, while the research on mandibular molars is few.This study aims to evaluate the therapeutic effect of mandibular molars distalization with clear aligner via cone beam CT (CBCT) and Dolphin software. Twenty cases of mandibular molars with clear aligner were included according to the inclusion and exclusion criteria. CBCT was taken before treatment (T0) and when the first molar was moved in place (T1). Dolphin software was used to measure the effectiveness of molar distalization. Three-dimensional changes in direction and the impact on the incisors and facial soft and hard tissues were evaluated. The effective rates of crown and root distalization of the second and first mandibular molars were 74%, 49%, and 71%, 47%, respectively. The second and first molars were both the distal buccal cusp with the largest distalization [(2.15 ± 0.91) mm and (1.85±1.09) mm], respectively, with significant difference between the T0 and T1 (P<0.05). The second and first molars were accompanied by depression, distal tilt, and buccal tilt with 1.06 mm, 2.10°, 2.27°, and 0.91 mm, 1.62°, and 1.91°, respectively, with significant differences between the T0 and T1 (all P<0.05). There was no obvious difference between men and women. The mandibular central incisor showed a lip-side movement of 1.02 mm, a depression of 0.82 mm, a mesial incline of 0.66°, and a crown-lip torque of 1.51° after molar distalization, with significant differences between the T0 and T1 (all P<0.001). Only the lower lip thickness increased by 0.1 cm, the length of the lower lip increased by 0.1 cm, and the ANS-ME (distance from anterior nasal spine to submental point) decreased by 0.13 cm, with significant differences between the T0 and T1 (all P<0.05). Clear aligner can effectively move mandibular molars farther, the crown is more effective than the root, and it is tilted. The second mandibular molar is more effective than the first mandibular molar in its distant displacement and three-dimensional changes. Molar distalization causes minor changes in mandibular incisors and facial soft and hard tissues.

Efficacy of clear aligners on mandibular molar distalization: A retrospective study

Background: Clear aligners (CAs) can distalize mandibular molars. The present study aimed to study the efficiency and influencing the factors of CAs for mandibular molar distalization and to provide guidance for clinical design. Materials and Methods: The present study evaluated 32 adult orthodontic patients who needed mandibular molar distalization and were treated with CAs between September 2018 and September 2020 at the school of medicine. The cone-beam computed tomography images of T0 (before orthodontic treatment) and T1 (after mandibular molars were fully distalized) were collected, and the actual movements of mandibular molars were measured and compared with the expected movements. The efficiency of mandibular molar distalization during treatment was comprehensively evaluated, and the relevant factors were analyzed. Results: For mandibular first molar distalization, the average efficiency of the crown was 67.19% 9swn. 13%, and that of the root was 37.87% 7stn. 72%. There was a significant difference between the achieved movement amount and the expected amount (P &lt; 0.05). For mandibular second molars, the average efficiency of the crown was 58.47% 7swn. 07%, and that of the root was 57.03% 3stn. 48%. There was a statistically significant difference between the achieved movement amount and the expected amount (P &lt; 0.05). There was a significant negative correlation between the expected movement and the efficiency of the crown. Conclusions: CAs can achieve mandibular molar distalization, and the movement pattern of molars is mainly a tipping movement. To accomplish bodily movement, overcorrection should be fully considered. In addition, it is suggested that close attention should be given to observing root movement during molar distalization.

Efficiency of class III malocclusion treatment with 2-premolar extraction and molar distalization protocols

Different treatment protocols have been implemented for management of Class III malocclusion with aim of achieving ideal occlusal goals. The aim of current study was to compare the efficiency of Class III treatment with mandibular 2-premolar extraction and mandibular molar distalization protocol. This retrospective cross sectional study was conducted on pre-treatment and post-treatment dental casts of 60 orthodontic patients who had Class III malocclusion and were treated with a mandibular dentition distalization and mandibular 2-premolars extraction protocol. The study was conducted at orthodontic departments of Dental Section, Faisalabad Medical University/Punjab Medical College and de'Montmorency College of Dentistry, Pakistan. The sample was classified into 2 groups. Group A consisted of 30 patients (20 females, 10 males) (mean age, 18.02years) treated with distalization protocol and Group B consisted of 30 patients (18 females, 12 males) (mean age, 18.97years) treated with mandibular 2-premolars extraction protocol. To compare the efficiency of the treatment protocol in each group, the initial and final occlusal results were assessed on dental models using PAR index while treatment efficiency was assessed using a treatment efficiency index (TX). The groups were compared with t and Mann-Whitney tests. There were no significant differences in the initial age, treatment time, treatment efficiency and any occlusal feature between the groups. Treatment efficiency of Class III malocclusions with mandibular 2-premolar extractions or mandibular dentition distalization protocol is similar.

Bone availability for mandibular molar distalization in adults with mandibular prognathism.

To investigate the retromolar space available for molar distalization in patients with mandibular prognathism. Using cone-beam computed tomography, the posterior mandibular dimensions in 110 consecutive patients with Class I or Class III malocclusion were measured (mean age, 27.0 ± 7.1 years). The shortest linear distances from the distal root of the right mandibular second molar to the inner border of the mandibular cortex were measured at the level of root furcation and 2, 4, and 6 mm apical to the furcation along the sagittal line and the posterior line of occlusion. The retromolar distances were compared between the Class I and Class III malocclusion groups using general linear mixed models. The retromolar space measured through the sagittal line showed no significant intergroup difference. Among the distances measured through the posterior line of occlusion, the space measured at depths 0 and 2 mm to the furcation were significantly greater in the Class III group than in the Class I group. Patients with Class III malocclusion have greater retromolar space for mandibular molar distalization along the posterior line of occlusion only at the level of the second molar furcation.

Biomechanical analysis of distalization of mandibular molars by placing a mini-plate: A finite element study.

ObjectiveThe objective of this study was to analyze the patterns of tooth movements when distalization of mandibular molars using a mini-plate took place. A finite element analysis was applied to analyze patterns of tooth movements.MethodsThe model of the mandible and teeth were used to build a finite element analysis model, and a mini-plate was inserted in the mandibular ramus. Two different orthodontic forces were established for displacement of mandibular molars. Orthodontic forces were applied at the level of the bracket and at the level of the cemento-enamel junction in the mandibular canine respectively.Resultsorthodontic forces at the level of the cemento-enamel junction resulted in a greater biomechanical bodily movement in distalization of the mandibular molars compared to when the orthodontic forces were applied at the level of the bracket. Applying orthodontic forces to the cemento-enamel junction also resulted in unwanted greater extrusive movements in distalization of the mandibular molars compared to the bracket level.ConclusionsWith considering the mode of orthodontic teeth movement, applying different vertical orthodontic forces for distalization of mandibular molars can lead to more effective distalization of teeth.

Treatment effects of mandibular total arch distalization using a ramal plate.

ObjectiveThe purpose of this study was to evaluate treatment effects after distalization of the mandibular dentition using ramal plates through lateral cephalograms.MethodsPre- and post-treatment lateral cephalograms and dental casts of 22 adult patients (11 males and 11 females; mean age, 23.9 ± 5.52 years) who received ramal plates for mandibular molar distalization were analyzed. The treatment effects and amount of distalization of the mandibular molars were calculated and tested for statistical significance. The significance level was set at p < 0.001.ResultsThe mandibular first molar distalization at the crown and root were 2.10 mm (p < 0.001) and 0.81 mm (p = 0.011), respectively. In the evaluation of skeletal variables, there was a significant increase in the Wits appraisal (p < 0.001). In the evaluation of the soft tissue, there was no significant effect on upper lip position, but the lower lips showed a significant retraction of 2.2 mm (p < 0.001).ConclusionsThe mandibular molars showed a significant amount of distalization accompanied by limited extrusion and mesiobuccal rotation of the crowns. A ramal plate may be a viable device for mandibular total arch distalization in Class III patients who are reluctant to undergo orthognathic surgery.

Is mandibular molar distalization feasible?

Introduction: The mandibular molar is considered the most difficult tooth to move. In certain clinical situations, it would seem useful to move it backward. Is that feasible? When would it be indicated? Is it successful, and if so how? Material and methods: We first review some fundamental principles and present an update of the literature on mandibular molar distalization, then analyze a retrospective series of 11 patients for whom mandibular molar distalization was planned. The movement achieved was studied on dental cephalometric superimposition with Delaire analysis. Results: the desired pure distal translation was achieved in 2 of the 11 cases; distalization was accompanied by coronary tip-back in 3 cases; in 4 cases, only coronary tipback was achieved, and apical tip-forward in 2 cases. Conclusion: Further studies are needed to determine optimally effective and reproducible distalization modalities for the mandibular molar.

Mandibular posterior anatomic limit for molar distalization

The purpose of this study was to investigate the mandibular posterior anatomic limit for molar distalization. Three-dimensional computed tomography scans were obtained on 34 adults with a skeletal Class I normodivergent facial profile and a normal occlusion. Posterior available space was measured at the crown and root levels along the posterior occlusal line connecting the buccal cusps of the first and second molars on the axial slices. It was also measured at the occlusal level on the lateral cephalograms derived from the computed tomography scans. The measurements on the cephalograms were used to predict the actual posterior available space determined by computed tomography and to determine the presence of root contact with the inner lingual cortex by linear regression and discriminant analyses, respectively. The posterior available space was significantly smaller at the root level than at the crown level. Root contact was observed in 35.3% of the 68 roots. The posterior available space measured on the lateral cephalograms resulted in a regression equation with a coefficient of determination of 0.261 to predict actual available space and correctly identified root contact in 66.2% of cases with a threshold value of 3.9mm. The posterior anatomic limit appeared to be the lingual cortex of the mandibular body. Computed tomography scans are recommended for patients who require significant mandibular molar distalization.

Miniscrew-Assisted Mandibular Molar Distalization in a Patient with Skeletal Class III Malocclusion: A Clinical Case Report

Miniscrew-Assisted Mandibular Molar Distalization in a Patient with Skeletal Class III Malocclusion: A Clinical Case Report

Miniscrew-assisted mandibular molar distalization in a patient with skeletal class-III malocclusion: A clinical case report

In nongrowing patients with mild skeletal Class-III malocclusion, premolar extraction or molar distalization in the lower arch can be done as a part of camouflage treatment. Temporary anchorage devices are widely used for this purpose because they do not produce undesirable reciprocal effects and do not depend on the patient's cooperation. However, most reported cases in this regard have used interradicular miniscrews in the mandibular arch and these have a risk of failure as they can loosen due to collision with adjacent roots. This article showcases mandibular molar distalization utilizing miniscrews, inserted at the retromolar area to correct a Class-III problem. A 24-year-old girl with a mild skeletal Class-III malocclusion and dental Class-III molar and canine relationship bilaterally was referred for orthodontic treatment. The treatment plan included distalization of the lower molars bilaterally followed by full fixed appliance therapy, after third molar extractions. For the lower molar distalization, the miniscrews were inserted at the retromolar pad. At the end of 21 months, a Class-I molar and canine relationship, normal overjet and overbite were obtained. The average amount of distalization of mandibular first molar was 3.2 mm at the crown level. In conclusion, placing miniscrews at the retromolar pad area for lower molar distalization was found to be a simple and effective method for correcting anterior cross bite and mandibular anterior crowding or protrusion, without the need for patient compliance.