Incisor position and alveolar bone thickness:: A comparative analysis of two untreated samples using lateral cephalograms

ObjectivesTo evaluate incisor position and its relationship to alveolar bone in untreated optimal occlusions and in untreated Class II malocclusions.Materials and MethodsFifty-seven lateral cephalograms of individuals with naturally occurring optimal occlusions (mean age = 23 years) were used to assess positions of central incisors and their relationships to alveolar bone. Data were compared to a sample of 57 individuals with untreated Class II malocclusions with concurrent anterior-posterior (AP) skeletal discrepancies (mean age = 16.9 years).ResultsSignificant intergroup differences were found for AP jaw relationship, maxillary alveolar bone thickness, mandibular incisor inclination, maxillary incisor root distance to labial surface of alveolar bone, and mandibular incisor root apex distance to labial surface of alveolar bone. Small differences between females and males existed for several variables. In both samples, maxillary incisor roots were located closer to the labial surface of alveolar process than to the palatal surface by roughly a 2:1 ratio. Mandibular incisor root apices were generally equidistant from the labial and lingual surfaces of the alveolus in the optimal sample but closer to the lingual surface in the Class II sample.ConclusionsMaxillary incisors tend to occupy the anterior one-third of the alveolus in untreated individuals, regardless of AP interarch dental relationships or AP jaw relationships. Mandibular incisor root apices tend to be centered within the alveolus in untreated optimal occlusions but are more positively inclined, and their root apices are more posterior in untreated Class II malocclusions.     

Alveolar bone response to light-force tipping and bodily movement in maxillary incisor advancement: A prospective randomized clinical trial

Objective:To compare alveolar bone thickness and height changes between untreated incisors (control), incisors advanced with light-force tipping, and incisors advanced with bodily movement mechanics.Materials and Methods:Forty-three subjects (aged 9.49 ± 1.56 years) with anterior crossbite were allocated into an untreated group (control), tipping group, or bodily movement group. Lateral cephalograms were taken before advancement (T₀) and after obtaining normal overjet (T₁). Changes in labial and palatal alveolar bone thickness and height surrounding maxillary incisors were evaluated with limited field-of-view cone-beam computed tomography before advancement (CT₀) and 4 months after normal overjet was obtained (CT₁). Wilcoxon matched-pairs signed-rank and Kruskal-Wallis one-way ANOVA tests were used to compare changes within and between groups, as appropriate. The significance level was set at .05.Results:Labial alveolar bone thickness at the midroot and apical levels were significantly decreased in the bodily movement group (P < .05). However, between groups, there was no statistically significant difference in labial bone thickness changes at any level. Palatal and total alveolar bone thickness at the midroot and apical levels were significantly decreased in the tipping group compared with the control and bodily movement groups (P < .05). Neither labial nor palatal bone height changes were significantly different among groups.Conclusions:Maxillary incisor advancement with light-force tipping and bodily movement in growing patients resulted in labial alveolar bone thickness and labial and palatal alveolar bone height changes that were similar to the untreated group.     

Effect of incisor position on the self-perceived psychosocial impacts of malocclusion among Chinese young adults

Objective:To evaluate the impact of the incisor position on the self-perceived psychosocial impacts of malocclusion among Chinese young adults.Materials and Methods:This cross-sectional study included a convenience sample of 17.1- to 22.3-year-old young adults (n  =  1005). The five groups represented were normal occlusion as well as incisor Class I, Class II/1, Class II/2, and Class III malocclusion. For clinical assessment, the incisor relationship was evaluated according to the British Standards Institute Incisor Classification, and the self-perception of dental esthetics was assessed using the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ). Statistical analysis involved the analysis of variance and Tukey multiple-comparison post hoc tests.Results:Psychosocial impacts were different among the five groups for the four PIDAQ domains (P < .001 for all four domains). Statistically significant differences were found between the four malocclusion groups and the normal occlusion group in all four domains (P < .001 for all four domains). Furthermore, statistically significant differences were found between four malocclusion groups.Conclusions:All four malocclusion groups had more severe psychosocial impacts than the normal occlusion group in the four PIDAQ domains. Statistically significant differences were also found between the four malocclusion groups; these malocclusion groups ranked by score, highest to lowest, were Class III, Class II/1, Class II/2, and Class I.     

Treatment outcomes of various force applications in growing patients with skeletal Class III malocclusion:: A comparative lateral cephalometric study

ObjectivesTo evaluate skeletal, dentoalveolar, and soft tissue changes between intraoral light force application and extraoral heavy force application in growing patients with skeletal Class III malocclusion.Materials andMethods: A retrospective study was conducted with pretreatment and posttreatment lateral cephalometric data from 50 subjects with skeletal Class III malocclusion. In the first group (15 boys, 10 girls; 8.67 ± 2.13 years old), each subject wore a biocreative horseshoe appliance (CHS) with two Class III elastics that exerted a force of 200 g. In the second group (13 boys, 12 girls; 8.96 ± 1.82 years old), each subject wore a Petit-type facemask and a lingual arch with hooks fixed to the maxillary arch with a total force of 700 g. Both groups of patients were instructed to wear the appliance approximately 14 hours a day, and 22 linear measurements and 8 angular measurements were evaluated. Changes of measurements from each group were compared by paired t-tests, considering a 5% significance level.ResultsForward growth of the maxilla, improvement of the maxilla–mandible relationship, and upper incisor flaring were achieved in both groups without any statistically significant difference between them. Lateral cephalometric analysis also showed that U1 exposure, IMPA (Angle between mandibular plane and mandibular incisor axis), FMIA (Angle between FH plan and mandibular incisor axis), and L1-APog (Angle formed by the intersection of tooth axis of lower incisor and A-Pog line, Distance from lower incisor edge to A-Pog line) showed statistically significant differences. Lower incisors were inclined lingually in the CHS group.ConclusionsDuring treatment of skeletal Class III malocclusion, the CHS with light Class III intermaxillary elastics therapy exhibits similar orthopedic changes to the maxillary complex and more dental changes to the lower anterior teeth compared with facemask therapy.     

成人骨性Ⅲ类错（牙合）患者下切牙区牙槽骨形态特征的CBCT初步研究

目的 研究成人骨性Ⅲ类错（牙合）患者下切牙区牙槽骨形态特征.方法 对17例成人骨性Ⅲ类错（牙合）患者及10例正常（牙合）对照者进行锥体束计算机断层（Cone beam computed tomography,CBCT）技术扫描拍摄,并对相关数据进行测量分析.结果 ①骨性Ⅲ类错（牙合）下切牙区牙槽骨厚度较正常（牙合）者薄（3.3±0.6） mm,其根尖点距唇侧骨皮质距离较近（0.8±0.4）mm（P＜0.01）;②骨性Ⅲ类错（牙合）牙槽骨附着高度较正常（牙合）者低,尤其是唇侧牙槽附着高度较低（5.2±1.3） mm（P＜0.01）;③下切牙倾斜度与牙槽骨厚度、唇侧牙槽附着高度、根尖点距唇侧牙槽骨距离具有相关性.结论 骨性Ⅲ类错（牙合）患者的下切牙区牙槽骨厚度较薄,唇侧牙槽骨附着高度较低并且与下切牙唇倾度有一定的相关性.临床中应重视成人骨性Ⅲ类错（牙合）患者的牙槽骨形态对于下切牙移动的影响.     

Correlation between periodontal soft tissue and hard tissue surrounding incisors in skeletal Class III patients

Objectives:To investigate the association between the periodontal soft tissue, alveolar bone and dental parameters surrounding the incisors at baseline in patients with skeletal Class III malocclusion.Materials and Methods:The study sample comprised 154 teeth from 28 patients with skeletal Class III malocclusion (19 men and 9 women, 21.15 ± 4.02 years). Periodontal soft tissue examination and hard tissue measurements with cone-beam computed tomography (CBCT) were performed. Factor analysis was used to reduce the CBCT variables, and correlation analysis between the hard tissue factors and soft tissue parameters was performed. Differences in hard tissue parameters between thick and thin gingival types were evaluated.Results:CBCT measurements were reduced to three hard tissue factors: lingual plate, coronal-buccal plate, and apical-buccal plate. Keratinized gingiva width and thickness were positively correlated with the coronal-buccal plate factor and negatively correlated with the apical-buccal plate factor. In the thin gingival biotype, mandibular incisors were more proclined, and the apical part of the buccal alveolar plate and the coronal part of lingual alveolar plate were thicker than in the thick gingival biotype.Conclusions:In the anterior teeth in cases of skeletal Class III malocclusion, hard tissue structures on the buccal side can be grouped based on coronal and apical factors that are significantly correlated with keratinized gingival width and thickness. Thick and thin gingival biotypes exhibited differences in tooth inclination and alveolar plate thickness with regard to the mandibular incisors.     

Alveolar bone response to maxillary incisor retraction using stable skeletal structures as a reference

ObjectivesTo evaluate alveolar bone change in relation to root position change after maxillary incisor retraction via cone-beam computed tomography (CBCT) using stable skeletal structures as a reference.Materials and MethodsA total of 17 subjects (age 24.7 ± 4.4 years) who required retraction of the maxillary incisors were included. Labial and palatal alveolar bone changes and root change were assessed from preretraction and 3 months postretraction CBCT images. The reference planes were based on stable skeletal structures. The Kruskal-Wallis test and Wilcoxon signed-rank test were used to compare changes within and between groups, as appropriate. Spearman rank correlations were used to identify the parameters that correlated with alveolar bone change. The significance level was set at .05.ResultsThe labial alveolar bone change after maxillary incisor retraction was statistically significant (P < .05), and the bone remodeling/tooth movement (B/T) ratio was 1:1. However, the palatal bone remained unchanged (P > .05). The change in inclination was significantly related to labial alveolar bone change.ConclusionsUsing stable skeletal structures as a reference, the change in labial alveolar bone followed tooth movement in an almost 1:1 B/T ratio. Palatal alveolar bone did not remodel following maxillary incisor retraction. The change in inclination was associated with alveolar bone change.     

Incisor inclination changes produced by two compliance-free Class II correction protocols for the treatment of mild to moderate Class II malocclusions

Objective:To compare the changes in incisor inclination between two compliance-free Class II correction protocols for the treatment of mild to moderate Class II malocclusions.Materials and Methods:Among Class II malocclusion patients a total of 38 consecutive patients treated with the Xbow appliance and later with full brackets (XB) were compared to 36 consecutive patients treated with Forsus connected to the archwire while on full brackets (FO). Evaluated cephalometric variables were overjet, overbite, skeletal Class II, lower incisor inclination, and upper incisor inclination. Factors that were analyzed were gender, treatment type, age at start of treatment (T1), and treatment length. Independent t-tests, χ², multiple analysis of variance, and Pearson correlations were applied.Results:No differences in incisor inclination between both treatment protocols were identified. At T1 no statistical difference for any cephalometric variable was demonstrated with regard to gender and treatment type. Gender was also not associated with a different treatment time or age at T1. The mean treatment time was 24.2 months for XB and 30.2 months for the FO group (P  =  .037). XB patients averaged 10 fewer months of fixed edgewise appliances compared to FO patients. Neither gender nor treatment type had any influence on the changes of the evaluated dependent variables between T1 and the end of treatment. Lower incisors proclined more the longer the treatment (P  =  .005). Both overjet and upper incisor inclination were affected by age at T1 (P  =  .001 and P  =  .014, respectively).Conclusions:Both compliance-free Class II correction protocols for the treatment of mild to moderate Class II malocclusions appear to generate the same amount of incisor inclination. Large variability was identified.     

The effect of platelet-rich fibrin (PRF) on maxillary incisor retraction rate

ObjectiveTo investigate the efficiency of platelet-rich fibrin (PRF) injection on maxillary incisor retraction rate.Materials and MethodsThe study included 40 patients (23 women and 17 men; mean age; 20.7 ± 1.45) with Class II Division 1 malocclusion. The treatment plan for all patients was extraction of the maxillary first premolars and canine distalization, followed by retraction of the maxillary incisors. Patients were randomly divided into two groups. The study group received injectable platelet-rich fibrin (i-PRF) two times with an interval of 2 weeks; the control group did not receive i-PRF. In both groups, the measurements were bilaterally assessed as the distances between the lateral and canine teeth on the plaster models at five time points. The rate of incisor movement was evaluated by Student''s t-test, analysis of variance, and Tukey honestly significant difference tests. Statistical significance was set as P < .05.ResultsThe average movements of incisors were significantly higher in the study group than the control group at all time points (P < .05). According to the within-group comparison, none of the measurements showed any significant differences between the right and left sides in both groups at all time points (P > .05). While the movement of incisors was significantly higher in the study group in the week following the PRF injection compared to the other weeks (P < .05), there were no significant differences in the control group at all-time points (P > .05).ConclusionsApplying i-PRF significantly increased the rate of maxillary incisor retraction at all time intervals. Platelet-rich fibrin injection can be an effective method for shortening treatment duration.     

微种植体支抗辅助内收上切牙后牙槽骨改建的锥形束CT研究

目的:探索运用微种植体支抗结合高位牵引钩大量内收上颌切牙后牙槽骨的改建情况。方法:以22例青少年上颌前突拔牙矫治患者,上颌切牙内收前、内收完成后的锥形束CT（cone-beam CT,CBCT）为研究样本,应用Mimics 15.0行CBCT影像三维重建,明确上颌切牙移动方式,利用Invivo5.0三维定点测量唇、腭侧牙槽骨厚度和高度变化。采用SPSS19.0 软件包对测量数据进行配对t 检验。结果:上颌切牙切缘与根尖均发生水平舌侧移动,但切缘的移动距离大于根尖;切缘点发生向下移动,根尖点出现明显的向上移动。上切牙腭侧牙槽骨厚度及唇腭侧总厚度在根颈1/3和根中1/3均显著减小（P<0.05）,而根尖1/3显著增加（P<0.05）,腭侧牙槽骨高度显著降低（P<0.05）。结论:青少年上颌前突患者微种植体支抗结合高位牵引钩可以实现受控制的倾斜移动。大量内收上颌切牙后,其腭侧牙槽骨吸收远大于唇侧增生,牙槽骨并没有完全跟随牙的移动而改建,提示正畸矫治时不宜过度内收前牙。     

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.     

后牙反[牙合]骨性安氏Ⅲ类错[牙合]早期矫治后腭的变化

目的：探讨以乳磨牙为支抗的上腭快速扩大联合前牵引矫治早期骨性Ⅲ类错[牙合]合并后牙反[牙合]畸形患者腭形态的变化。方法：12例替牙早期骨性Ⅲ类错[牙合]合并后牙反[牙合]病例,第一阶段Hyrax支架式上腭快速扩大器扩大2—3周至上颌牙舌尖咬在下颌牙颊尖。第二阶段前牵引至前牙覆盖2～4mm,对矫治前后模型进行腭形态测量。结果：腭底宽增加1．98mm±0．97mm,磨牙距增加5．04mm±1．30mm,腭底宽增加量／磨牙距的增加量为41％,上颌牙槽突夹角增加8．57°±4．05°,左磨牙的倾斜角颊倾8．99°±4．06°,右磨牙的倾斜角颊倾8．34°±3．94°,变化均有显著性差异。腭深度改变无显著性差异。结论：上腭快速扩大联合前牵引是矫治替牙早期骨性Ⅲ类错[牙合]合并后牙反[牙合]畸形的较好方法,腭底宽、磨牙距、上颌牙槽突夹角、磨牙倾斜角的增加均有显著性差异。腭的明显变化使畸形的上腭趋向正常。     

Three-dimensional Analysis of Lip Changes in Response To Simulated Maxillary Incisor Advancement

ObjectiveTo assess the immediate response of lips in three dimensions (3D) resulting from simulated maxillary incisor advancement.Materials and MethodsIncremental maxillary incisor advancement was simulated by placing wax of increasing thickness (+2 mm, +4 mm, +6 mm) on the incisors of 20 participants, and the induced lip changes were recorded using 3D stereophotogrammetry. The induced displacement of lip landmarks was quantified using 3D image analysis software. Data were analyzed using a repeated-measures analysis of variance (ANOVA) after adjusting for age and sex of the study participants.ResultsA large interindividual variation in lip response to simulated incisor advancement was observed. A significant overall effect on 3D lip changes was found for increasing values of simulated incisor advancement (F = 13.2; P < .001) as well as significant differences between anatomical landmarks of the lip (F = 7.4; P < .01). Most points moved outward and anterosuperiorly, except the midpoint and corners of the lip. Greatest movement was observed in the sagittal plane, followed by the vertical and transverse planes.ConclusionsMaxillary incisor advancement significantly affects upper lip change in three planes of space: particularly the anteroposterior plane, in which the response to simulated advancement appears to be nonlinear.     

Periodontal consequences of mandibular incisor proclination during presurgical orthodontic treatment in Class III malocclusion patients

Objective:To test the hypothesis that periodontal changes are similar between proclined and minimal-changed mandibular incisor position groups during presurgical orthodontic treatment for Class III orthognathic surgery.Materials and Methods:The following measurements were performed before and after presurgical orthodontic treatment of 75 patients (proclination group, 39 subjects; minimal-change group, 36 subjects): clinical crown length, sulcus and bone probing depths, and width of attached gingiva from clinical examination; infradentale-to-MP (perpendicular distance of infradentale to mandibular plane) from examination of lateral cephalograms; and the distance between the cementoenamel junction and alveolar crest from examination of periapical radiographs. Data were compared between the two groups, and a regression analysis was performed to investigate factors affecting the periodontal changes.Results:In both groups, clinical crown length and bone probing depth increased during presurgical orthodontics (P < .05). Infradentale-to-MP and the width of attached gingiva decreased more in the proclination group than in the minimal-change group (P < .05). Proclination and protrusion of the mandibular incisors, and treatment duration affected the periodontal changes.Conclusions:The null hypothesis was rejected. Proclination of the mandibular incisors for decompensation in Class III surgery patients seems to result in labial alveolar bone recession and a decrease in width of attached gingiva. However, the amount of the periodontal recession appeared to be clinically insignificant.     

骨皮质切开术辅助上切牙内收后对牙根及牙槽骨影响的锥形束CT研究

目的 探讨骨皮质切开术辅助上切牙内收后对上颌切牙牙根吸收、牙槽骨厚度和牙槽骨高度的影响.方法 招募20例拔除两个上颌第一前磨牙的骨性Ⅱ类1分类错牙合畸形患者,分为骨皮质切开术组(n=10)和对照组(n=10).矫治前后拍摄锥形束CT,测量两组矫治前后上颌切牙牙根长度、牙槽骨厚度和牙槽骨丧失高度.结果 骨皮质切开术组矫治...     

安氏Ⅱ类1分类和2分类成人患者上颌中切牙根尖区牙槽骨厚度分析

目的　运用锥形束CT（CBCT）对比安氏Ⅱ类1分类和2分类成人患者与正常牙合成人上颌中切牙根尖区牙槽骨厚度，为正畸牙齿移动提供参考。方法　选取2017年2月至2018年10月就诊于山西医科大学第一医院正畸科的安氏Ⅱ类1分类、安氏Ⅱ类2分类成人患者各20例，另选取个别正常牙合成人20名，每位研究对象均拍摄CBCT。分别测量各分组研究对象的左、右上颌中切牙倾斜度∠U1-SN和∠U1-PP，上颌中切牙根尖区唇侧牙槽骨厚度、舌侧牙槽骨厚度及牙槽骨总厚度，将测量结果进行统计分析。 结果　（1）上颌中切牙根尖区唇侧牙槽骨厚度：安氏Ⅱ类2分类组小于安氏Ⅱ类1分类组和正常牙合牙合组；（2）上颌中切牙根尖区舌侧牙槽骨厚度：安氏Ⅱ类2分类组>正常牙合组>安氏Ⅱ类1分类组；（3）上颌中切牙根尖区牙槽骨总厚度：安氏Ⅱ类1分类组小于安氏Ⅱ类2分类组和正常牙合组；（4）安氏Ⅱ类错牙合，上颌中切牙唇倾度增大，根尖区唇侧牙槽骨厚度增加、舌侧牙槽骨厚度减小、牙槽骨总厚度减小。结论　对于安氏Ⅱ类错牙合患者的治疗，应结合牙槽骨厚度制定最佳矫治方案，以防止出现医源性牙槽骨缺损。     

Upper airway changes after Xbow appliance therapy evaluated with cone beam computed tomography

Objective:To determine the treatment effects of the Xbow appliance on the upper airway dimensions and volume using cone-beam computed tomography (CBCT); to evaluate the cephalometric changes in the skeletal and dental structures of the skeletal Class II patients.Materials and Methods:The sample consisted of 25 Class II patients (11 male, 14 female) with a mean age of 11.1 ± 1.1 years. CBCT images were obtained at the beginning of the treatment (T0) and after the debonding of the Xbow (T1).Results:Changes in superior, middle, and inferior parts of the oropharynx in the retroglossal region and changes in the oropharyngeal airway volume were statistically significant (P < .05, P < .01). The differences favoring the Xbow for the changes in the direction of Class II correction included SNA, SNB, ANB, maxillary depth angles, and point A-NPg and Co-B distances. Data of the dental parameters showed palatal tipping and extrusion of the maxillary incisors, labial tipping of the mandibular incisors, and mesial movement and extrusion of the mandibular molars.Conclusions:Treatment with the Xbow appliance in Class II patients resulted in favorable increase in the oropharyngeal airway dimensions and volume. Further studies with larger study samples and with control groups are needed.     

Alveolar bone thickness and height changes following incisor retraction treatment with microimplants:: A cone beam computed tomography study

ObjectivesTo evaluate alveolar bone remodeling following incisor retraction treatment with microimplants and to examine the relationship between crown/root distal movement and thickness/height changes of the alveolus.Materials and MethodsA total of 24 patients (mean age, 19.29 ± 4.64 years) with bialveolar protrusion treated by incisor retraction with microimplants were included. The distances of the crown and root tip movements as well as the thickness (alveolar bone thickness [ABT]; labial, lingual, and total) and vertical level (vertical bone level [VBL]; labial and lingual) of the alveolar bone were assessed using cone-beam computed tomography images obtained before treatment (T1) and after treatment (T2). All T1 and T2 variables were compared, and further comparisons of alveolar bone changes were conducted between the two groups based on the distance of the crown (low-crown-movement and high-crown-movement groups) and root movements (low-root-movement and high-root-movement groups). To determine the correlation of the crown or root movement with the variables of alveolar bone changes, Pearson correlation coefficients were calculated.ResultsSignificant differences were found in all VBL and ABT variables after treatment in both jaws but not in total ABT. Based on the crown and root movements, alveolar bone change significantly differed between the root-movement groups, whereas there was no significant difference between the crown-movement groups. In addition, root movement showed significant correlations with the variables.ConclusionsRemarkable changes in the height and thickness of alveolar bone were found after microimplant-aided incisor retraction treatment in all groups except for total ABT. Root movement was significantly correlated with the alveolar bone changes.     

Comparison of arch width,alveolar width and buccolingual inclination of teeth between Class II division 1 malocclusion and Class I occlusion

Objective:To compare the arch width, alveolar width, and buccolingual inclination of maxillary and mandibular posterior teeth between Class II division 1 malocclusion and Class I occlusion.Materials and Methods:Forty-five subjects with Class I occlusion and 45 subjects with Class II division 1 malocclusion were selected to measure the maxillary and mandibular arch width and alveolar width of premolars and first molars with digital caliper. Buccolingual inclination of maxillary and mandibular premolars and first molars were measured with a modified universal bevel protractor.Results:All of the posterior teeth in both groups were lingually tilted. The maxillary premolars and first molars were significantly more lingually tilted (P < .05) in Class II division 1 malocclusion than in Class I occlusion. Mandibular first premolars were significantly less lingually tilted in Class II division 1 malocclusion than in Class I occlusion. No significant difference of buccolingual inclination was found in mandibular second premolars and first molars between the two groups. No significant difference in maxillary and mandibular arch width and alveolar width was found between the two groups.Conclusions:Buccolingual inclination rather than arch width and alveolar width plays an important role in transverse discrepancy of Class II division 1 malocclusion.     

Retrognathic maxilla in individuals born with oral clefts is due to intrinsic factors and not only due to early surgical treatment

ObjectivesTo determine if the skeletal form of individuals born with oral clefts was associated with maxillary position.Materials and MethodsLateral cephalometric radiographs of 90 individuals 8 to 12 years old born with or without cleft lip and palate paired by age and sex were used. Skull base length, cranial base angle, cranial deflection angle, and maxillary skeletal length and position were studied. Also, mandibular skeletal length and position, lower anterior facial height, and dental position were defined. Individuals were divided into three groups: 30 individuals born with cleft lip and palate with Class III malocclusion (UCLP Class III), 30 individuals born with cleft lip and palate with Class I malocclusion (UCLP Class I), and 30 individuals born without cleft lip and palate with Class III malocclusion (non-cleft Class III).ResultsWhen comparing the UCLP Class III group with the UCLP Class I group, there were differences in maxillary position (P < .001) and mandibular position (P = .004) found. No differences were found when comparing the UCLP Class III group with the non-cleft Class III group.ConclusionsThere are intrinsic factors that affect craniofacial morphology of individuals born with cleft lip and palate.