Short- and long-term evaluation of mandibular dental arch dimensional changes in patients treated with a lip bumper during mixed dentition followed by fixed appliances

Objective:To evaluate short- and long-term mandibular dental arch changes in patients treated with a lip bumper during the mixed dentition followed by fixed appliances, compared with a matched control sample.Materials and Methods:Dental casts and lateral cephalograms obtained from 31 consecutively treated patients before (T₀) and after (T₁) lip bumper, after fixed appliances (T₂), and a minimum of 3 years after fixed appliances (T₃) were analyzed. The control group was matched as closely as possible. Arch width, arch perimeter, arch length, and incisor proclination were evaluated. Repeated measures ANOVA was used to analyze changes in measurements over all four time points between treatment and control groups.Results:Arch widths and crowding were always significantly different except at T₂−T₁. At T₁−T₀, only crowding decreased 3.2 mm while intercanine, interpremolar, and intermolar widths increased by 3.8, 3.3, and 3.9 mm, respectively. Changes at T₃−T₂ showed a significant decrease of 2.1 mm for crowding and an increase of 3.5, 2.9, 2.7, and 0.8 mm for intercanine, interpremolar, and intermolar widths and arch perimeter, respectively. Finally, at T₃−T₀, the reduction in crowding of 5.03 mm was significant and clinically important in the treated group. The differences between intercanine, interpremolar, and intermolar widths were also significant (2.1, 3.8, and 3.6 mm, respectively). All those differences favored the treated group.Conclusions:Mandibular dental arch dimensions were significantly changed after lip bumper treatment. At follow-up, all arch widths were slightly decreased, generating an increase of 0.4 mm in crowding, considered clinically irrelevant. Overall changes remained stable after an average 6.3-year follow-up.     

Maxillary arch changes with transpalatal arch treatment followed by full fixed appliances

Objective:To evaluate short- and long-term maxillary dental arch dimensional changes in patients treated with a transpalatal arch (TPA) during mixed dentition followed by full fixed appliances in the permanent dentition compared with an untreated sample.Materials and Methods:Dental casts and lateral cephalograms obtained from 36 consecutively treated patients before TPA treatment (T₀), after TPA treatment (T₁), after fixed appliance treatment (T₂), and a minimum of 3 years after fixed appliance treatment (T₃) were analyzed. The control group was matched as closely as possible. Arch widths, perimeter, and length, as well as crowding and incisor proclination, were evaluated.Results:In the treated group, intercanine, interpremolar, and intermolar widths and arch perimeter increased significantly at T₁. At T₂, only the intercanine width increase was still significant. At T₃ all arch dimensions decreased, remaining larger than they were at T₀. The arch length increased after T₁, significantly decreased at T₂, and slightly decreased at T₃. The crowding decreased significantly at T₁, was eliminated at T₂, and increased at T₃. At T_3, 50% of the patients showed relapse with crowding ranging from 0.5 to 2 mm. In the control group at T1, only slight changes were noted but crowding increased. At T2, crowding and upper incisor inclination increased but arch length decreased. At T3, intercuspid width, arch perimeter, and arch length continued to decrease, thereby increasing crowding.Conclusion:Maxillary dental arch dimensions changed significantly after TPA followed by treatment with fixed appliances. Relapse occurred to some extent, especially in intercanine width and arch perimeter, but most of the dental arch changes remained stable.     

Long-term stability of combined rapid palatal expansion-lip bumper therapy followed by full fixed appliances.

INTRODUCTION: The purpose of this study was to evaluate the long-term postretention stability of rapid palatal expansion-lip bumper therapy followed by full fixed appliances. METHODS: The sample included 20 treated patients (11 women and 9 men) who were recalled to obtain postretention records. The subjects were out of retention for a minimum of 4 years and an average of 7.9 years. They had begun treatment in the late mixed dentition at a mean age of 11.1 with considerable incisor crowding but, on average, no tooth size-arch length discrepancies. Pretreatment, posttreatment (mean age, 13.6 years), and postretention (mean age, 24.3 years) models were digitized, and the computed measurements were compared with untreated reference data. RESULTS: The majority of treatment increases in maxillary and mandibular arch dimensions were statistically significant (P < .05) and greater than expected for untreated controls. Although many measurements decreased postretention, net gains were maintained for 21 of the 30 measurements evaluated. The notable exception was arch perimeter, which decreased to less than pretreatment values. Postretention incisor irregularity increased 0.5 +/- 1.2 mm in the maxillary arch and 1.1 +/- 1.5 mm in the mandibular arch. CONCLUSIONS: Based on the good long-term stability observed in this study, we concluded that use of rapid palatal expansion-lip bumper expansion therapy in the late mixed dentition followed by full fixed appliances is an effective form of treatment for patients with up to moderate tooth size-arch length discrepancies.     

Long-Term Effects of Rapid Maxillary Expansion Followed by Fixed Appliances

Objective:To evaluate the long-term changes in maxillary arch widths, overjet, and overbite in patients who were treated with rapid maxillary expansion (RME) followed by edgewise appliances.Materials and Methods:The material for the study consisted of study casts taken from 41 patients (19 males, 22 females) on four different occasions (before treatment, T1; after RME, T2; after treatment, T3; and during follow-up period, T4). The upper intercanine, interpremolar, and intermolar widths and overjet and overbite were measured on each set of study casts. Mean age of the subjects was 13.2 ± 1.3 years (range, 11.2–16.9 years) at T1, 13.3 ± 1.3 years (range, 11.3–17 years) at T2, 15.5 ± 1.4 years (range, 13.1–18.8 years) at T3, and 20.4 ± 1.6 years (range, 17.9–24.8 years) at T4.Results:The net increase in intercanine width, interpremolar width, intermolar width, overjet, and overbite was 1.4 ± 2.4 mm, 4.6 ± 2.6 mm, 4.3 ± 2.5 mm, 0.1 ± 0.6 mm, and 0.2 ± 0.6 mm, respectively, and the relapse rates were 37% for intercanine width, 19% for interpremolar width, and 17% for intermolar width at the end of the follow-up period.Conclusions:A significant amount of relapse occurred in maxillary arch widths at the postretention assessment, the greatest being in intercanine width. RME significantly decreased overbite and increased overjet, and a statistically significant decrease was observed in both overbite and overjet at the postretention assessment.     

Relapse tendency in maxillary arch width in unilateral cleft lip and palate patients with different maxillary arch forms.

OBJECTIVE: The aim of this study was to investigate the relapse tendency in the maxillary dental arch widths in unilateral cleft lip and palate patients with different types of maxillary arch form. SUBJECTS: Thirty-two unilateral cleft lip and palate patients treated by one-stage surgical palatal closure were included. The subjects were divided into three groups according to the types of the maxillary arch forms: group A, symmetrical arch form; group B, collapse of minor segment; group C, collapse of both segments. METHODS: Using dental casts obtained at three different times, relapse in the intercanine, interpremolar, and intermolar widths in each group was assessed and differences between groups were investigated. Results: Patients in group A showed stable results in all measurements. Patients in group B showed posttreatment relapse in the intercanine width only, whereas patients in group C demonstrated significant posttreatment relapses in the interpremolar and intermolar widths. Comparison between groups showed more significant relapse in the interpremolar and intermolar widths of group C than in those of group B. CONCLUSION: The types of the maxillary arch forms in unilateral cleft lip and palate patients might play a stronger role in the stability of the maxillary dental arch widths after orthodontic treatment in patients with collapse of both segments and a severe degree of maxillary narrowness.     

The effects of maxillary expansion using a quad-helix appliance during the deciduous and mixed dentitions

Ten subjects, five in the deciduous dentition and five in the mixed dentition (x̄ age = 6 years 9 months), had functional posterior cross-bites successfully corrected with fixed lingual arch wire expansion appliances of the quad-helix design. The appliance, in the context of “early” treatment, produced midpalatal suture separation on each subject as evidenced on occlusal radiographs. While the relative orthopedic and orthodontic changes were not determined, the maxillary intermolar and intercanine transverse measurements showed significant increases in all subjects, with mean values of +5.3 mm. and +4.1 mm., respectively. The active phase of treatment averaged 30 days and 1.1 adjustments for the desired expansion to be achieved. Incorporating a standard 6-week retention period, the total appliance wear time had a mean value of 75 days. Following a 3-month postretention adjustment period, relapse of the intermolar and intercanine transverse dimensions presented mean decreases of −1.5 mm. and −1.9 mm., respectively. The relapse potential was successfully compensated for by overexpansion of 2 to 3 mm. during the active phase of treatment. No significant differences were demonstrated between the deciduous- and mixed-dentition groups during the course of maxillary expansion with the quad-helix appliance.     

Long-term stability of lip bumper therapy followed by fixed appliances

Lip bumper treatment has been shown to successfully increase arch width, procline the incisors, and distalize molars. However, few studies have been performed showing the long-term stability of lip bumper treatment. In this study, mandibular casts taken by a single practitioner from 51 patients treated with lip bumpers without rapid palatal expansion were analyzed at pretreatment, post-lip bumper treatment, posttreatment, and long-term out of treatment. Measurements of arch width, arch depth, arch length, and anterior crowding were made. During treatment, there was a mean decrease in irregularity of 3.73 mm, with a posttreatment increase of 0.76 mm, for a net decrease of 2.97 mm. Despite posttreatment decreases, significant gains in arch width were maintained for extended periods of time. The intercanine width had a net increase of 1.78 mm (19% relapse), first premolars 3.39 mm (26% relapse), second premolars 2.58 mm (34% relapse), and first molars 2.17 mm (20% relapse). Lip bumper treatment along with fixed appliances is an effective means to obtain long-term increases in arch width and decreases in the irregularity index.     

Stability of anterior crossbite correction: A randomized controlled trial with a 2-year follow-up

Objective:To compare and evaluate the stability of correction of anterior crossbite in the mixed dentition by fixed or removable appliance therapy.Material and Methods:The subjects were 64 consecutive patients who met the following inclusion criteria: early to late mixed dentition, anterior crossbite affecting one or more incisors, no inherent skeletal Class III discrepancy, moderate space deficiency, a nonextraction treatment plan, and no previous orthodontic treatment. The study was designed as a randomized controlled trial with two parallel arms. The patients were randomized for treatment with a removable appliance with protruding springs or with a fixed appliance with multibrackets. The outcome measures were success rates for crossbite correction, overjet, overbite, and arch length. Measurements were made on study casts before treatment (T0), at the end of the retention period (T1), and 2 years after retention (T2).Results:At T1 the anterior crossbite had been corrected in all patients in the fixed appliance group and all except one in the removable appliance group. At T2, almost all treatment results remained stable and equal in both groups. From T0 to T1, minor differences were observed between the fixed and removable appliance groups with respect to changes in overjet, overbite, and arch length measurements. These changes had no clinical implications and remained unaltered at T2.Conclusions:In the mixed dentition, anterior crossbite affecting one or more incisors can be successfully corrected by either fixed or removable appliances with similar long-term stability; thus, either type of appliance can be recommended.     

上下颌唇挡对替牙晚期儿童牙(牙合)的影响

目的研究上下颌唇挡同时应用对替牙晚期儿童牙(牙合)的影响.方法选择替牙晚期上下牙列轻度或中度拥挤患儿12例,上下颌均采用唇挡治疗8个月,进行治疗前后X线头影测量分析和模型测量分析,并对治疗前后的测量值变化进行配对t检验.结果唇挡治疗后,SNA、SNB分别增加1.02°和0.97°(P＜0.05),上下切牙前移均是牙冠向近中倾斜,而根尖相对固定的控制性倾斜,旋转中心接近根尖.上下磨牙远中倾斜效果不同,上磨牙远中倾斜直立,旋转中心接近牙冠;下磨牙远中倾斜移动,旋转中心接近阻抗中心;上颌磨牙间牙弓宽度、牙弓周径分别增加4.12mm和5.09mm(P＜0.01),下颌磨牙间牙弓宽度、牙弓周径分别增加4.07mm和6.86mm(P＜0.01).结论在儿童生长发育高峰期,唇挡可有效地引起上下颌牙弓横向和纵向变化,减轻或解除上下牙弓拥挤.     

自锁托槽非拔牙矫治下牙列拥挤的临床研究

目的 比较自锁托槽和传统结扎式托槽非拔牙矫治牙列拥挤患者的下牙列变化,探讨自锁托槽解除牙列拥挤的机制.方法 选择26例下牙列拥挤患者,分为自锁组和传统组,每组13例,分别使用自锁托槽(Damon3)和传统托槽(传统结扎式托槽)进行非拔牙矫治.对矫治前后变化进行配对t检验,逐步回归分析拥挤解除机制以及影响下切牙唇倾度改变量的相关因素.结果 矫治前后两组患者下颌尖牙间、前磨牙间牙弓宽度改变量及下切牙唇倾度改变量比较,差异均无统计学意义(P>0.1);矫治后自锁组下颌第一磨牙间牙弓宽度增加1.42 mm、下切牙凸距增加2.66 mm,传统组下颌第一磨牙间牙弓宽度增加0.65 mm、下切牙凸距增加1.57 mm,两组比较,差异有统计学意义(P<0.1).回归分析显示,自锁组对下切牙唇倾度变化量解释的总测定系数高达96.6%,被选入模型的变量为矫治前下颌拥挤度、下颌平面角、第一磨牙间牙弓宽度,以及矫治前后尖牙及第一前磨牙间牙弓宽度改变量.结论 非拔牙矫治下牙列拥挤时,自锁组和传统组患者均出现下切牙唇倾及下牙弓宽度增加,自锁组第一磨牙间牙弓宽度增加量及下切牙前移量较传统组多;自锁组下切牙唇倾度的改变不仅受拥挤度和矫治前牙弓宽度影响,而且受患者自身骨面型及牙弓宽度变化的影响.     

欧米加阻挡曲扩弓法排齐和整平下颌拥挤牙列效果的临床研究

目的 评价下颌非拔牙病例中,澳丝弯制的欧米加阻挡曲扩弓法在传统直丝弓托槽上排齐和整平下颌拥挤牙列方面的临床效果。方法 选择58例正畸患者,年龄19~24岁,随机均分成2组,各29例,一组接受传统矫治方法,另一组采用欧米加阻挡曲扩弓法矫治。每种矫正方法又分为轻-中度拥挤（5 > Ⅱ > 2）和重度拥挤（Ⅱ > 5）两个亚组。下颌治疗结束时间以下牙弓完全排齐和整平为准。头颅侧位片评价下牙弓排齐和整平前后下切牙位置的变化;模型上测量下尖牙间距和下第一恒磨牙间距以反映牙弓宽度的变化。结果 2种排齐和整平的方法获得了相同程度的前牙区和后牙区扩弓量;就重度拥挤病例而言,欧米加阻挡曲扩弓法要明显快于传统方法（P=0.017）;结论 2种方法无论在切牙的唇向移动程度还是尖牙间距和磨牙间距的扩大情况等各方面几乎获得了同样的效果,对于严重拥挤的牙列,欧米加阻挡曲扩弓装置显示出更高的效率,是非常值得推荐的一种矫正方法。     

A long-term study on the expansion effects of the cervical-pull facebow with and without rapid maxillary expansion

This study evaluates the long-term stability of maxillary expansion achieved by widening the inner bow of a facebow, with or without concurrent rapid maxillary expansion (RME) (Haas type), followed by treatment with fixed edgewise appliances. The parent sample included 154 nonextraction patients who started their orthodontic treatment during a defined time period. The exclusion criteria reduced the number of patients to 61 in the cervical-pull facebow group (CFB) and 41 in the RME-CFB group. All subjects were in the late-mixed to early-permanent dentition stage at the start of treatment. Dental casts were measured using a digital imaging system at four different times: start of treatment (T1), end of active treatment (T2), end of retention (T3), and postretention follow up (T4). The RME-CFB protocol produced a greater increase in maxillary arch width (6.1 mm) than did the CFB protocol (4 mm). The RME-CFB protocol provided greater net maxillary arch perimeter increase than did expansion with an inner bow of a cervical facebow. The RME-CFB group had three mm more arch perimeter 10 years after treatment completion than did the CFB group. The stability of expansion achieved with an inner bow of a facebow was equal to that achieved with a Haas-type RME appliance. Both expansion protocols retained 90% of the initial intermolar expansion 15 years after expansion.     

螺旋缩弓器治疗单侧后牙正锁的长期效果观察

目的：评价正畸螺旋缩弓器和MBT直丝弓矫治技术治疗单侧正锁后上颌牙弓宽度、前牙覆和覆盖的长期变化。方法：对23名（男13,女10）经正畸治疗后的患者4个阶段（治疗前,T1;螺旋缩弓后,T2;MBT治疗后,T3和去除保持器后2年,T4）的模型进行测量分析。结果：缩弓后上颌牙弓宽度明显减小（P〈0.05）。MBT治疗后尖牙宽度复发明显（P〈0.05）。停戴保持器2年后,尖牙宽度、第一前磨牙宽度、第一磨牙宽度、前牙覆和覆盖分别净减小（1.2±0.96）mm,（3.9±1.19）mm,（4.6±0.23）mm,（1.8±0.42）mm,（0.8±0.13）mm。结论：单侧正锁经正畸螺旋缩弓器和MBT直丝弓矫治技术治疗后上颌牙弓宽度稳定。     

Longitudinal clinical study on the effect of slow maxillary expansion with removable appliances

The aim of this clinical study was to evaluate the longitudinal changes in dental arches in patients treated with a slow maxillary expansion appliance in primary dentition or early mixed dentitionMethodsThe sample consisted of 19 children (13 girls and 6 boys) with a narrowing of the maxillary arch. The mean ages at the start, at the end of expansion, and at the final follow-up (1 year 7 months after the retention) were 7 years 10 months, 8 years 10 months and 12 years 4 months, respectively. The mean expansion period was 1 year and the mean retention period after the expansion was 1 year 11 months. The control group consisted of 28 Japanese persons with untreated normal occlusion.ResultsThe results were as follows. (1) At the end of the expansion, the maxillary dental arch width increased remarkably, and there was no significant difference in comparison with the control group. (2) At the follow-up after the retention, although the maxillary intercanine width was significantly smaller than the control group, the maxillary intermolar width stabilized during retention and there was no significant difference in comparison with the control group. (3) The mandibular intermolar width gradually increased during the maxillary expansion.ConclusionThis clinical study demonstrated that this type of treatment using a slow maxillary expansion appliance in primary dentition or early mixed dentition is effective and stable in the long term for the maxillary molar regions. Furthermore, it was suggested that the lateral development of the mandibular dental arch could be promoted by expanding the maxillary dental arch width.     

Stability of transverse expansion in the mandibular arch.

This was a retrospective, longitudinal cephalometric and cast study of 29 white patients at pretreatment, posttreatment, and an average of 6 years 3 months postretention. The goal was to assess changes with treatment and retention with the expanding mandibular lingual arch appliance in conjunction with fixed edgewise treatment. Seven mandibular cast measurements were assessed, including arch crowding, arch perimeter, arch length, and arch width at the permanent canines, first premolars, second premolars, and first molars. Cephalometric radiographs were digitized, and 16 cephalometric measurements were made. Repeated-measures analysis of variance and 2-sample t tests were used to determine statistically significant changes. It was found that the expanding lingual arch used for less than 6 months with the mandibular fixed edgewise appliance caused an increase in both the transverse and sagittal dimensions of the mandibular dental arch. Transverse expansion was more stable in the posterior region of the mandibular dental arch than in the anterior region. Mandibular intercanine width increase could be maintained only by fixed retention. Although the maxillary and mandibular incisors were advanced and proclined, lip protrusion did not occur.     

Dental Arch and Cephalometric Changes Following Treatment for Class III Malocclusion by Means of the Function Regulator (FR-3) Appliance

AIM: The aim of this retrospective clinical study was to evaluate dental arch, skeletal, dentoalveolar, and soft tissue profile changes following treatment of Class III malocclusion by means of the Function Regulator (FR-3) appliance. SUBJECTS AND METHODS: The study sample consisted of 14 growing patients (seven boys and seven girls) with a mean age of 9.7 +/- 1.1 years presenting Class III malocclusion. They were treated with an FR-3 appliance exclusively for a period of 2.4 +/- 0.6 years. Dental casts and lateral cephalometric radiographs were obtained immediately before initiation and after completion of treatment with the FR-3 appliance. Thirteen variables were used for the dental cast analysis and 61 variables for the cephalometric analysis. The paired t-test was utilized to evaluate the presence of significant changes (p < 0.05). RESULTS: The evaluation of the dental casts revealed that there was a significant increase in intermolar, interpremolar, and intercanine width of the maxilla and of palatal height after treatment. Concerning the mandible, an increase in intermolar and intercanine width and a decrease in lower arch depth were observed. Cephalometric evaluation revealed a significant decrease in SNB angle and an increase in ANB angle, overjet, facial convexity, nose prominence, and lower soft tissue face height. There was an increase in upper lip thickness and a decrease in lower lip convexity observed after treatment. CONCLUSIONS: The results of this study confirm a favorable functional and esthetic maxillary and mandibular position following treatment by means of the function regulator (FR-3) appliance.     

Total arch maxillary distalization using infrazygomatic crest miniscrews in the treatment of Class II malocclusion: a prospective study

ObjectivesTo evaluate treatment effects in Class II patients using infrazygomatic crest (IZC) miniscrews (MS).Materials and MethodsA prospective sample of 25 adolescents (14 females and 11 males; mean age: 13.6 ± 1.5 years) who underwent maxillary dentition distalization treatment with IZC MSs were recruited. Lateral cephalograms and digital models at the beginning of treatment (T1) and after Class II molar correction (T2) were obtained. To compare cephalometric and digital model changes, paired t-test and Wilcoxon test were used. A significance level of 5% was used.ResultsAll patients achieved Class II molar correction over a mean period of 7.7 ± 2.5 months. The IZC MS therapy provided 4 mm of distalization; there was 1.2 mm of intrusion of the first molar with 11.2° distal tipping. The maxillary incisors were retracted 4.7 mm and tipped lingually 13.4°. Overjet and overbite showed a reduction of 3.6 mm and 2.4 mm, respectively. The occlusal plane rotated clockwise 2.8°. The upper lip was retracted by 1 mm and the nasolabial angle increased 5.1°. There was an increase in the interpremolar and intermolar distances.ConclusionsTotal arch distalization of the maxillary dentition using IZC MS was effective in the treatment of Class II malocclusions.     

The stability of the arch-expansion effects of Fr?nkel appliance therapy

To assess the long-term stability of the arch expansion effects of the functional regulator, mandibular dental casts were evaluated for treatment and postretention changes in intercanine width, width between first premolars, width between second premolars, intermolar width, incisor irregularity, and arch length. This study was comprised of 11 cases that were treated with the Fr?nkel appliance (mean = 27 mo.) and were and average of 4 years and 4 months out of active treatment. Results showed overall stability to be good, with some variability present in individual responses. Intercanine width, width of first premolars, width of second premolars, and intermolar width all demonstrated maintenance of treatment increases. Correction of incisor irregularity displayed better stability than has been reported in other stability studies. Arch length decreased with treatment and continued to decrease during the postretention period, although to a lesser extent than has been previously reported. The results of this study support the statements of Fr?nkel concerning the stability of this type of arch expansion.     

Relapse of incisor crowding: A visit to the prince of salina

The management of the retention period after comprehensive orthodontic treatment is of great importance, as a primary goal of clinician. Considerable controversy still surrounds the problem of stability after the retention period. Many studies analyze factors associated to the presence of crowding or incisor irregularity and find predictive features on its relapse. Most studies have reported little o no correlation between the treatment changes in the biological parameters - clinical, biometric (irregularity index, intermolar width, intercanine width, arch length, overjet, overbite), or cephalometric variables- that ocurred and the posttretament and postretention changes that may predict their future development. This article provides a bibliographical overview on the relapse of dental alignment in treated cases. In a brief historical introduction, the first studies on the long-term stability of orthodontic results are analysed. The article then goes on to assess studies that focus attention on anteroinferior alignment before finally studying relapse of upper crowding. It concludes by making some final comments in the light of the bibliography provided and the differents schools regarding retention needs and methods. Key words:Retention, stability, irregularity, dental alignment.     

Nonextraction orthodontic therapy: posttreatment dental and skeletal stability

To assess the long-term stability of nonextraction orthodontic treatment, the dental cast and cephalometric records of 28 cases were evaluated. Thirty cephalometric and seven cast parameters were examined before treatment, posttreatment, and an average of almost 8 years postretention. Results showed overall long-term stability to be relatively good. Relapse patterns seen were similar in nature, but intermediate in extent, between untreated normals and four first premolar extraction cases. Significant decreases were seen in arch length and intercanine width during the postretention period despite minimal changes during treatment. Incisor irregularly increased slightly postretention; intermolar width, overjet, and overbite displayed considerable long-term stability. Mandibular incisor mesiodistal and faciolingual dimensions were not associated with either pretreatment or posttreatment incisor crowding. Class II malocclusions with large ANB values and shorter mandibular lengths showed increased incisor irregularity, shorter arch lengths, and deeper overbites at the postretention stage, suggesting that the amount and direction of facial growth may have been partially responsible for maturational changes seen during the postretention period.