A prospective clinical trial of the effects produced by the Connecticut intrusion arch on the maxillary dental arch

ObjectiveTo assess and compare the effects produced in the maxillary dental arch by means of Connecticut intrusion arch (CIA) with or without a cinch back on the distal end of the tube of the first molars.Materials and MethodsThis study included 44 patients with a mean age of 13.1 ± 1.8 years treated for deep bite with a CIA randomly divided into two groups: group 1 (G1), 22 patients with initial mean age of 12.72 ± 1.74 years treated with the CIA in the upper arch without a cinch back on the distal surface of the tube of the first molars, and group 2 (G2), 22 patients with an initial mean age of 13.67 ± 2.03 years treated with the CIA with a cinch back. Lateral cephalograms were available before treatment (T1) and after intrusion of maxillary incisors (T2). The mean treatment period was 5.5 ± 1.45 months. Intragroup and intergroup changes in the maxillary incisor and molar positions were analyzed by paired and independent t-tests associated with the Holm-Bonferroni correction method for multiple comparisons (P < .05).ResultsThere were significant differences between groups in terms of maxillary incisor displacement. The maxillary incisors flared labially (2.17°) and proclined (1.68 mm) in group 1, whereas a palatal inclination (−1.99°) and retroclination (−1.13 mm) was observed in group 2. No significant differences were found for the molar positions between the groups.ConclusionsThe presence or absence of a distal bend in CIA affects incisor tipping and proclination during intrusion mechanics.     

Response of the maxillary dentition to a statically determinate one-couple system with tip-back mechanics: A prospective clinical trial

Objective:To quantify the effects of tip-back mechanics on the maxillary first molars and incisors.Materials and Methods:Sixteen subjects with Class II end-on malocclusion were treated with an intrusion arch to achieve distalization of the maxillary molar through tip-back mechanics. Lateral cephalograms were taken prior to molar tip-back (T1), after molar tip-back (T2), and after molar root uprighting (T3). Data were analyzed using the Friedman’s and Wilcoxon signed rank tests to evaluate differences in time points (P ≤ .016).Results:The maxillary first molar distalized 1.53 mm (P = .001) with 6.65° (P = .001) of distal tipping and 0.86 mm (P = .001) of extrusion at T2. Minor relapse of the first molar (mesial direction) was seen at T3. The maxillary incisors flared labially 0.4 mm, and the incisor root apex moved palatally 1.19 mm (P = .005) at T2. At T3, the incisor root apex moved palatally 1.5 mm (P = .003) from T1. An angular change from T1 of 3.31° (P = .008) and 3.53° (P = .014) was seen at T2 and T3, respectively, as a result of palatal root movement of the maxillary incisors.Conclusions:A significant amount of distalization of maxillary molars was attained at the crown level with tip-back mechanics. Palatal root angulation change was significant in the incisors with minimal anteroposterior movement of the incisal edge.     

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目的    探讨横腭弓在上颌唇向错位尖牙远中移动时对支抗的控制。方法    对2008年10月至2009年10月广东医学院附属南山医院口腔科收治的60例上颌尖牙唇侧错位患者。按就诊顺序随机分为试验组和对照组，每组30例。所有患者均用横腭弓加强支抗，横腭弓Ω曲朝向近中。试验组在错位尖牙舌窝黏舌侧扣，用弹力线将舌侧扣和Ω曲相连加力，在尖牙远移时实现支抗控制；对照组常规治疗。结果    试验组和对照组上颌磨牙均发生近中移动，其中对照组磨牙倾斜移动较大。模型测量： 矫治前后上颌尖牙（U3）牙尖间宽度的差值试验组较对照组小，试验组差值为（1.15 ±0.73）mm，对照组差值为（2.1 ±1.13）mm，两者比较差异有统计学意义（P < 0.05）。矫治前后上颌第一磨牙至腭大孔连线的距离（U6-PP）的差值试验组较对照组小，试验组差值为（1.17 ±0.39）mm，对照组差值为（2.05 ±0.37）mm，两者比较差异有统计学意义（P < 0.05）。结论    在尖牙远移过程中，横腭弓舌侧拉尖牙远移有利于控制尖牙宽度，保持弓形，减少后牙支抗的损耗。     

Effectiveness of the transpalatal arch in controlling orthodontic anchorage in maxillary premolar extraction cases: A systematic review and meta-analysis

Objective:To evaluate the effectiveness of the transpalatal arch (TPA) as an anchorage device in preventing maxillary molar mesialization during retraction of the anterior teeth after premolar extraction.Materials and Methods:This systematic review intended to include patients indicated for upper premolar bilateral extraction and subsequent retraction of anterior teeth, considering the use of TPA as an anchorage tool in one of the treatment groups. The search was systematically performed, up to April 2015, in the following electronic databases: Medline, Embase, and all evidence-based medicine reviews via OVID, Cochrane Library, Scopus, PubMed, and Web of Science. Risk of bias assessment was performed using Cochrane''s Risk of Bias Tool for randomized clinical trials (RCTs) and Methodological Index for Nonrandomized Studies (MINORS) for non-RCTs.Results:Fourteen articles were finally included. Nine RCTs and five non-RCTs presented moderate to high risk of bias. Only one study investigated the use of TPA in comparison with no anchorage, failing to show significant differences regarding molar anchorage loss. A meta-analysis showed a significant increase in anchorage control when temporary anchorage devices were compared with TPA (mean difference [MD] 2.09 [95% confidence interval {CI} 1.80 to 2.38], seven trials), TPA + headgear (MD 1.71 [95% CI 0.81 to 2.6], four trials), and TPA + utility arch (MD 0.63 [95% CI 0.12 to 1.15], 3 trials).Conclusion:Based on mostly moderate risk of bias and with some certainty level, TPA alone should not be recommended to provide maximum anchorage during retraction of anterior teeth in extraction cases.     

Combined use of miniscrews and continuous arch for intrusive root movement of incisors in Class II division 2 with gummy smile

Adequate intrusion and torque control of the retroclined maxillary incisors are critical for the treatment of Class II division 2 (div2) malocclusion. In addition, anterior retraction via lingual root movement can be challenging. This case report demonstrates a combined use of miniscrews and continuous arch with additional torque for intrusion, retraction, and torque control of maxillary incisors in the Class II div2 with gummy smile. A 20-year-old woman presented with multiple issues, including impacted canine, lip protrusion, prolonged retained mandibular primary molar, and two missing maxillary premolars. In order to improve her facial profile and eliminate the need for prosthetic work, the mandibular primary molar and contralateral premolar were extracted. Two miniscrews were placed at the maxillary buccal alveolar bone to apply the posterosuperior force for retraction of anterior teeth, with additional labial crown torque on the arch wire. The results were the intrusion (4 mm) and lingual root movement (17°) of the maxillary incisors without anchorage loss of maxillary molars, flattening of the Curve of Spee, and Class I molar relation that were maintained after 50 months of retention period. The combined use of miniscrews and continuous arch could be a reliable and effective treatment modality for torque control and intrusion of retroclined maxillary incisors in the Class II div2 patient.     

A comparative study of the effect of the intrusion arch and straight wire mechanics on incisor root resorption: A randomized,controlled trial

Objective:To analyze and compare external apical root resorption (EARR) of maxillary incisors treated by intrusion arch or continuous archwire mechanics.Materials and Methods:This cone-beam computed tomography (CBCT) study analyzed 28 deep bite patients in the permanent dentition who were randomly divided into two groups: Group 1, 12 patients with initial mean age of 15.1 ± 1.6 years and mean overbite of 4.6 ± 1.2 mm treated with the Connecticut intrusion arch (CIA) in the upper arch (Ortho Organizers, Carlsbad, Calif) for a mean period of 5.8 ± 1.27 months. Group 2, 16 patients with initial mean age of 22.1 ± 5.7 years and mean overbite of 4.1 ± 1.1 mm treated with conventional leveling and alignment using continuous archwire mechanics for 6.1 ± 0.81 months. The degree of EARR was detected in 112 maxillary incisors by using CBCT scans and a three-dimensional program (Dolphin 11.7, Dolphin Imaging & Management Solutions, Chatsworth, Calif). The CBCT scans were obtained before (T1) and 6 months after initiation of treatment (T2). Differences between and within groups were assessed by nonpaired and paired t-tests, respectively, with a 5% significance level.Results:Significant differences were found for both groups between T1 and T2 (P < .05) indicating that EARR occurred in both groups. However, there were no significant differences when EARR was compared between group 1 (−0.76 mm) and group 2 (−0.59 mm).Conclusions:The Connecticut intrusion arch did not lead to greater EARR of maxillary incisors when compared with conventional orthodontic mechanics.     

Cone-beam computerized tomography evaluation of canine retraction using micro implant and conventional anchorage

ObjectiveVarious anchorage techniques have been designed for canine retraction. The aim was to measure and compare the rate of canine retraction with conventional method and micro implant using CBCT.Materials and methodsSample size comprising of 17 subjects were scheduled for extraction of all first premolars. After leveling and aligning, titanium micro implants were placed between the roots of the second premolar and the first molars on right side, in both the arches. Pre and post retraction CBCT scans were taken. Retraction was done using sliding mechanics using stainless steel arch wire.ResultsThe maxillary right canine (micro implant) retracted by 6.75 mm and tipped distally by 9.51° at a rate of 1.05 mm/month while the mandibular right canine retracted by 4.83 mm and tipped distally by 7.88° at a rate of 1.13 mm/month. On the left side (conventional) with molar as a source of anchorage, maxillary canine retracted by 6.03 mm and tipped distally by 6.51° at a rate of 1.46 mm/month while the mandibular canine retracted by 5.03 mm and tipped distally by 4.34° at a rate of 1.15 mm/month.ConclusionImplants can serve as a source of anchorage.     

Distalization pattern of the maxillary arch depending on the number of orthodontic miniscrews

Objective:To determine the effects of linear force vector(s) from interradicular miniscrews on the distalization pattern of the maxillary arch in adult Class II patients.Materials and Methods:Twenty-five adult patients with mild to moderate Class II dentition and minimal crowding were collected. Either single (group A, n  =  12) or dual (group B, n  =  13) miniscrews were inserted on the posterior interradicular area to deliver a distalizing force to the main archwire. The displacement patterns of maxillary incisors and molars were measured and compared.Results:Significant distalization in the molars and incisors was shown in both groups. Significantly greater distalization and intrusion of the first molar and intrusive displacement of the incisor, together with significant reduction of the mandibular plane, were noted in group B, in contrast to the rotation of the occlusal plane in group A.Conclusions:Interradicular miniscrews predictably induced total arch distalization, leading to the correction of Class II. Additional miniscrews in the premolar area appear to facilitate intrusion and distalization of the entire arch according to the position of the force vectors.     

利用压低辅弓增加后牙支抗的生物力学研究

目的确定远中移动尖牙时,使用压低辅弓增加后牙支抗的最适后倾弯角度。方法按照Burstone方法弯制0．017×0．025英寸（1英寸-2．54cm）伊钛丝（TMA）的压低辅弓,主弓丝采用0．016×0．016英寸不锈钢丝,拉尖牙远中移动的拉簧为150g力。设计后倾弯分别为20°、30°、40°,采用口外正畸模拟生物力学检测系统（OrthodonticMeasurementandSimulationSystem,（）Mss）模拟临床加力,分别测量三维状态下切牙段、尖牙段和后牙段受力和力矩情况。结果尖牙远移过程中,无压低辅弓时,尖牙远中移动并倾斜,磨牙近中倾斜10°;压低辅弓的后倾弯为20°时,尖牙远中移动并倾斜,磨牙近中倾斜5°;后倾弯为30°时,尖牙远中移动基本保持直立,磨牙远中倾斜5°;后倾弯为10。时,尖牙远中移动有压低倾向,磨牙远中倾斜超过10°。结论尖牙远中移动时,弯制有30。后倾弯的乐低辅弓既能够增加后牙专精．又不影响前牙的覆[牙合]覆盖。     

A comparison of treatment effects of total arch distalization using modified C-palatal plate vs buccal miniscrews

Objective:The purpose of this study was to compare the treatment effects of palatally vs buccally placed temporary anchorage devices.Materials and Methods:Of 40 Class II division 1 malocclusion patients, 22 were treated with modified C-palatal plate (MCPP) appliances (age 21.9 ± 6.6 years), and 18 (age 24.2 ± 6.8 years) were treated with buccally placed miniscrews between the maxillary first molar and second premolar. A total of 26 linear and angular measurements were analyzed on pre- and posttreatment lateral cephalograms. Multivariate analysis of variance was performed to evaluate the treatment effects within each group and to compare the effects between groups.Results:Overall, the MCPP appliances showed 4.2 mm of distalization, 1.6 mm of intrusion of the first molar with 2° tipping, and 0.8 mm extrusion of incisors. The miniscrew group resulted in 2.0 mm of distalization, 0.1 mm intrusion of the first molar with 7.2° tipping, and 0.3 mm of incisor extrusion. Regarding soft tissue change, in the MCPP group, the upper lip was significantly retracted (P < .001).Conclusions:Comparing the treatment effects between MCPP appliances and buccal miniscrews, the MCPP appliances showed greater distalization and intrusion with less distal tipping of the first molar and more extrusion of the incisor compared to the buccal miniscrews.     

Maxillary canine retraction with self-ligating and conventional brackets: A randomized clinical trial

Objective:To measure space closure during the retraction of upper permanent canines with self-ligating and conventional brackets.Materials and Methods:Fifteen patients who required maxillary canine retraction into first premolar extraction sites as part of their orthodontic treatment completed this study. In a random split-mouth design, the retraction of upper canines was performed using an elastomeric chain with 150 g of force. The evaluations were performed in dental casts (T0, initial; T1, 4 weeks; T2, 8 weeks; T3, 12 weeks). The amount of movement and the rotation of the canines as well as anchorage loss of the upper first molars were evaluated.Results:There was no difference between self-ligating and conventional brackets regarding the distal movement of upper canines and mesial movement of first molars (P > .05). Rotation of the upper canines was minimized with self-ligating brackets (P < .05).Conclusion:Distal movement of the upper canines and anchorage loss of the first molars were similar with both conventional and self-ligating brackets. Rotation of the upper canines during sliding mechanics was minimized with self-ligating brackets.     

Tooth movement rate and anchorage lost during canine retraction: A maxillary and mandibular comparison

Objectives:To investigate the canine retraction rate and anchorage loss during canine retraction using self-ligating (SL) brackets and conventional (CV) brackets. Differences between maxillary and mandibular rates were computed.Materials and Methods:Twenty-five subjects requiring four first premolar extractions were enrolled in this split-mouth, randomized clinical trial. Each patient had one upper canine and one lower canine bonded randomly with SL brackets and the other canines with CV brackets but never on the same side. NiTi retraction springs were used to retract canines (100 g force). Maxillary and mandibular superimpositions, using cephalometric 45° oblique radiographs at the beginning and at the end of canine retraction, were used to calculate the changes and rates during canine retraction. Paired t-tests were used to compare side and jaw effects.Results:The SL and CV brackets did not show differences related to monthly canine movement in the maxilla (0.71 mm and 0.72 mm, respectively) or in the mandible (0.54 mm and 0.60 mm, respectively). Rates of anchorage loss in the maxilla and in the mandible also did not show differences between the SL and CV brackets. Maxillary canines showed greater amount of tooth movement per month than mandibular canines (0.71 mm and 0.57 mm, respectively).Conclusions:SL brackets did not show faster canine retraction compared with CV brackets nor less anchorage loss. The maxillary canines showed a greater rate of tooth movement than the mandibular canines; however, no difference in anchorage loss between the maxillary and mandibular posterior segments during canine retraction was found.     

Initial forces experienced by the anterior and posterior teeth during dental-anchored or skeletal-anchored en masse retraction in vitro

Objective:To investigate initial forces acting on teeth around the arch during en masse retraction using an in vitro Orthodontic SIMulator (OSIM).Materials and Methods:The OSIM was used to represent the full maxillary arch in a case wherein both first premolars had been extracted. Dental and skeletal anchorage to a posted archwire and skeletal anchorage to a 10-mm power arm were all simulated. A 0.019 × 0.025-inch stainless steel archwire was used in all cases, and 15-mm light nickel-titanium springs were activated to approximately 150 g on both sides of the arch. A sample size of n = 40 springs were tested for each of the three groups. Multivariate analysis of variance (α = 0.05) was used to determine differences between treatment groups.Results:In the anterior segment, it was found that skeletal anchorage with power arms generated the largest retraction force (P < .001). The largest vertical forces on the unit were generated using skeletal anchorage, followed by skeletal anchorage with power arms, and finally dental anchorage. Power arms were found to generate larger intrusive forces on the lateral incisors and extrusive forces on the canines than on other groups. For the posterior anchorage unit, dental anchorage generated the largest protraction and palatal forces. Negligible forces were measured for both skeletal anchorage groups. Vertical forces on the posterior unit were minimal in all cases (<0.1 N).Conclusions:All retraction methods produced sufficient forces to retract the anterior teeth during en masse retraction. Skeletal anchorage reduced forces on the posterior teeth but introduced greater vertical forces on the anterior teeth.     

Canine retraction and anchorage loss: Self-ligating versus conventional brackets in a randomized split-mouth study

Objective:To evaluate the velocity of canine retraction, anchorage loss and changes on canine and first molar inclinations using self-ligating and conventional brackets.Materials and Methods:Twenty-five adults with Class I malocclusion and a treatment plan involving extractions of four first premolars were selected for this randomized split-mouth control trial. Patients had either conventional or self-ligating brackets bonded to maxillary canines randomly. Retraction was accomplished using 100-g nickel-titanium closed coil springs, which were reactivated every 4 weeks. Oblique radiographs were taken before and after canine retraction was completed, and the cephalograms were superimposed on stable structures of the maxilla. Cephalometric points were digitized twice by a blinded operator for error control, and the following landmarks were collected: canine cusp and apex horizontal changes, molar cusp and apex horizontal changes, and angulation changes in canines and molars. The blinded data, which were normally distributed, were analyzed through paired t-tests for group differences.Results:No differences were found between the two groups for all variables tested.Conclusions:Both brackets showed the same velocity of canine retraction and loss of anteroposterior anchorage of the molars. No changes were found between brackets regarding the inclination of canines and first molars.     

Changes in Occlusal Relationships in Mixed Dentition Patients Treated with Rapid Maxillary Expansion: A Prospective Clinical Study

Objective:To prospectively measure occlusal changes in mixed dentition patients who underwent a standardized early expansion protocol.Materials and Methods:The treatment sample consisted of 500 patients who were assigned to three groups according to molar relationship: Class I (n  =  204), end-to-end (n  =  166), and Class II (n  =  130). All patients were treated with a bonded rapid maxillary expander (RME) followed by a removable maintenance plate and a transpalatal arch. Mean age at the start of treatment was 8.8 years (T₁), with a pre–phase 2 treatment cephalogram (T₂) taken 3.7 years later. The control sample consisted of the cephalometric records of 188 untreated subjects (Class 1, n  =  79; end-to-end, n  =  51; Class II, n  =  58).Results:The largest change in molar relationship was noted when the Class II treatment group (1.8 mm) was compared with the matched control group (0.3 mm). A positive change was seen in 81% of the Class II treatment group, with almost half of the group improving by ≥2.0 mm. The end-to-end treatment group had a positive change of 1.4 mm, compared with a control value of 0.6 mm, and the Class I group of about 1 mm compared with controls, who remained unchanged (0.1 mm). Skeletal changes were not significant when any of the groups were compared with controls.Conclusion:The expansion protocol had a significantly favorable effect on the sagittal occlusal relationships of Class II, end-to-end, and Class I patients treated in the early mixed dentition.     

Interseptal bone reduction on the rate of maxillary canine retraction

Objective:To propose and evaluate a novel surgical approach with minimal trauma, termed interseptal bone reduction, combined with the use of a conventional orthodontic fixed appliance to accelerate canine retraction.Materials and Methods:A split-mouth design study was conducted in 18 female subjects (mean age, 21.9 years) whose bilateral upper first premolars were extracted and who subsequently received canine distalization. The extraction socket on the experimental side was deepened, and interseptal bone distal to the maxillary canine was reduced in thickness using a surgical bur; conventional extraction was performed on the control side. The canines were then distalized using elastomeric chains on both the labial and palatal sides, with a net force of 150 g. The extent of canine movement and rotation was determined from study models, and the angulation was analyzed based on lateral cephalograms.Results:A Wilcoxon signed rank test demonstrated that the extent of canine movement in the mesio-distal direction after 3 months was significantly greater on the experimental side than on the control side (5.4 and 3.4 mm, respectively, P  =  .002). However, there was no statistically significant difference in canine angulation or rotation after 3 months between the experimental and control sides.Conclusions:In combination with the use of conventional orthodontic appliances, interseptal bone reduction can enhance the rate of canine movement when interseptal bone is sufficiently reduced in both thickness and depth following surgical criteria.     

Dental archforms in dentoalveolar Class I,II and III

Objective:To test the hypothesis that no differences exist in dental arch dimensions between dentoalveolar Classes I, II, and III, and between male and female subjects, as measured on virtual three-dimensional (3D) models.Materials and Methods:Samples included randomly selected plaster dental casts of 137 white patients (43 Class I, 50 Class II, and 44 Class III) from the Department of Orthodontics, School of Dental Medicine, University of Zagreb, Croatia. Dental models were scanned and digitized using ATOS II SO (“Small Objects”) scanning technology (GOM mbH, Braunschweig, Germany). Eight linear and two proportional measurements were calculated for both upper and lower dental arches.Results:In men, a significant difference in the upper dental arch was present in the incisor region, and in the lower dental arch, differences were found in intercanine and intermolar widths (P < .05). Significant differences were noted between male groups in the upper molar depth dimension (P  =  .022) and in the lower molar and canine depth dimensions (P < .05). Class III males had the greatest lower molar and canine width/depth ratios and the smallest lower canine depth/molar depth ratio. Class III women had wider and shorter mandibular arches when compared with Class I and Class II females.Conclusion:The hypothesis was rejected. The dimensions of the dental arches are related to gender and to dentoalveolar class. Class I and II subjects have similar dimensions of maxillary dental arch, but Class II subjects have a transverse deficit in the mandible. In Class III subjects, the maxillary dental arch is insufficient in transverse and sagittal dimensions, and the mandibular arch dominates in the transverse but not in the sagittal dimension.     

压低辅弓增加后牙支抗的临床应用研究

目的：研究压低辅弓在尖牙远移过程中增加后牙支抗的临床效果。方法：选择需要强支抗,上颌减数第一双尖牙的患者30例,随机分为研究组和对照组,每组15例,研究组采用上颌NANCE弓,配合0.017＂×0.025＂TMA压低辅弓,30°后倾弯,150g力远中牵引尖牙至第二双尖牙,对照组采用上颌NANCE弓,配合口外弓。将矫治前后的头颅侧位定位片和三维模型进行对比分析,其变化量进行独立t检验。结果：研究组在尖牙远中移动的过程中,右侧上颌第一磨牙近中移动0.77mm,近中腭向扭转8.9°;左侧上颌第一磨牙近中移动约0.72mm,近中腭向扭转8.8°;右侧上颌尖牙远中移动约5.5mm,远中腭向扭转10.3°;左侧上颌尖牙远中移动约5.71mm,远中腭向扭转15.1°。与对照组相比无显著性差异。且第一磨牙在前后向的位移与尖牙的位移和磨牙的扭转存在高度相关性。结论：30°后倾弯的压低辅弓在远中移动尖牙过程中,可以为后牙提供强支抗。     

Maxillary anterior alignment stability in Class I and Class II malocclusions treated with or without extraction

Objective:To compare the postretention stability of maxillary incisors alignment in subjects with Class I and II malocclusion treated with or without extractions.Materials and Methods:The sample comprised 103 subjects with initial maxillary anterior irregularity greater than 3 mm and was divided into four groups: group 1 comprised 19 patients with Class I malocclusion treated with nonextraction (mean initial age = 13.06 years); group 2 comprised 19 patients with Class II malocclusion treated with nonextraction (mean initial age = 12.54 years); group 3 comprised 30 patients with Class I malocclusion treated with extractions (mean initial age = 13.16 years); group 4 comprised 35 patients with Class II malocclusion treated with extractions (mean initial age = 12.99 years). Dental casts were obtained at three different stages: pretreatment (T1), posttreatment (T2), and long-term posttreatment (T3). Maxillary incisor irregularity and arch dimensions were evaluated. Intergroup comparisons were performed by one-way analysis of variance followed by Tukey tests.Results:In the long-term posttreatment period, relapse of maxillary crowding and arch dimensions was similar in all groups.Conclusion:Changes in maxillary anterior alignment in Class I and Class II malocclusions treated with nonextractions and with extractions were similar in the long-term posttreatment period.     

Three-dimensional analysis of molar compensation in patients with facial asymmetry and mandibular prognathism

Objective:To evaluate the characteristic transverse dental compensations in patients with facial asymmetry and mandibular prognathism and to compare features of dental compensations between two types of mandibular asymmetry using 3-dimensional (3D) cone-beam computed tomography (CBCT).Materials and Methods:Seventy-eight adult patients with skeletal Class I (control group; n  =  33; 19 men and 14 women) or skeletal Class III with facial asymmetry (experimental group; n  =  45; 23 men and 22 women) were included. The experimental group was subdivided into two groups according to the type of mandibular asymmetry: translation type (T-type; n  =  20) and roll type (R-type; n  =  19). CBCT images were acquired before orthodontic treatment and 3D analyses were performed.Results:The transverse dental distance was significantly different between the two groups only at the palatal root apex of the maxillary first molar (P < .05). In the experimental group, the first molar axes were compensated significantly on both arches except the maxillary nondeviated side. The vertical molar heights were different between the two groups only on the maxillary arch (P < .001). The R-type showed greater mandibular ramal length difference and menton deviation than the T-type (P < .001). In the R-type, transverse compensation of the maxillary first molars was more obvious than with the T-type, which resulted in canting in the maxillary occlusal plane.Conclusions:Mandibular asymmetry with prognathism showed a characteristic transverse dental compensation pattern. The mandibular asymmetry type influenced the amount and direction of molar compensation on the maxillary arch.