Postretention Stage Research Articles

External root resorption (ERR) and rapid maxillary expansion (RME) at post-retention stage: a comparison between tooth-borne and bone-borne RME

BackgroundThe study aimed to compare external root resorption (ERR) three-dimensionally in subjects treated with tooth-borne (TB) versus bone-borne (BB) rapid maxillary expansion (RME). Forty subjects who received tooth-borne RME (TB group, average age 13.3 years ± 1.10 years) or bone-borne RME (BB group, average age 14.7 ± 1.15 years) were assessed using CBCT imaging before treatment (T0) and after a 6-month retention period (T1). 3D reconstructions of the radicular anatomy of maxillary first molars (M1), first and second premolars (P1 and P2) were generated to calculate volumetric (mean and percentage values) and shape changes (deviation analysis of the radicular models) obtained at each time point. 2D assessment of radicular length changes was also performed for each tooth. Data were statistically analyzed to perform intra-group (different teeth) and inter-group comparisons.ResultsIn both groups, all the investigated teeth showed a significant reduction in radicular volume and length (p < 0.05), with the first molars being the teeth most affected by the resorption process (volume and palatal root length). When volumetric radicular changes were calculated as a percentage of the pre-treatment volumes, no differences were found among the investigated teeth (p > 0.05). Based on the deviation analysis from radicular models superimposition, the areas most affected by shape change were the apex and bucco-medial root surface. Overall, the amount of ERR was significantly greater in the TB group (mm3: M1 = 17.03, P1 = 6.42, P2 = 5.26) compared to the BB group (mm3: M1 = 3.11, P1 = 1.04, P2 = 1.24).ConclusionsDespite the statistical significance, the difference in the amount of ERR of the posterior maxillary dentition between TB-RME and BB-RME remains clinically questionable.

Relapse of anterior crowding 3 and 33years postretention.

The aim of this study was to evaluate the relapse of occlusal characteristics and maxillary and mandibular anterior crowding 3 and 33years postretention. The sample comprised 28 patients, 15 Class I and 13 Class II, treated with 4 premolar extractions, with a mean initial age of 12.72years (SD, 0.99), a mean final age of 14.74years (SD, 1.26), and a mean treatment time of 2.02years (SD, 0.66). The mean short-term postretention age was 20.15years (SD, 1.34), and the mean long-term postretention age was 49.40years (SD, 4.54). The mean time of short-term postretention evaluation was 3.70years (SD, 0.87) and the mean long-term postretention evaluation was 32.95years (SD, 4.31). The maxillary and mandibular irregularity indexes were assessed on the initial, final, short-term, and long-term postretention stage dental casts. Peer Assessment Rating and the Little indexes were compared among the 4 stages by repeated measures analysis of variance and Tukey tests. Peer Assessment Rating index and maxillary anterior crowding were significantly improved with treatment, had significant relapses in the short term, and a slight and not statistically significant increase from short-term to long-term postretention evaluation. The mandibular irregularity index significantly decreased with treatment, and then significantly and progressively increased in the postretention stages. The occlusal characteristics and maxillary anterior crowding had significant relapses in the short term and remained stable from the short-term to the long-term postretention stages. Mandibular anterior crowding significantly decreased with treatment, showed a significant relapse in the short term, and continued to significantly increase in the long-term postretention stage.

Influence of treatment including second molars on final and postretention molar angulation

Evaluate axial mesiodistal inclinations of the mandibular molars in orthodontically treated cases, analyzing whether inclusion of second mandibular molars in treatment mechanics has any influence on final and postretention molars angulations. The sample comprised 150 panoramic radiographs of 50 patients. Patients were treated with extraction of four first premolars and divided into 2 groups: Group 1 comprised 25 subjects without inclusion of mandibular second molars during orthodontic treatment, whereas Group 2 comprised 25 subjects with inclusion of mandibular second molars. Panoramic radiographs at three observation times were evaluated: pretreatment, posttreatment and postretention. The statistical analysis included one-way analysis of variance (ANOVA) for intragroup evaluation and independent t-tests for intergroup comparisons. Intragroup analysis demonstrated significant uprighting of mandibular first and second molars during treatment in Group 2, which remained stable during the postretention stage. Intergroup comparison demonstrated that Group 2 presented first and second molars significantly more uprighted in relation to Group 1 in both post-treatment and postretention stages. It was concluded that inclusion of mandibular second molars in the orthodontic mechanics is relevant not only to correct the angulation of these teeth, but also to aid mandibular first molars uprighting.

Stability of molar relationship after non-extraction Class II malocclusion treatment

This study aimed to evaluate the stability of molar relationship after non-extraction treatment of Class II malocclusion. The sample comprised 39 subjects (16 females, 23 males) with initial Class II malocclusion treated with no extractions, using fixed appliances. Mean age at the beginning of treatment was 12.94 years, at the end of treatment was 15.14 years and at post-retention stage was 21.18 years. Mean treatment time was 2.19 years and mean time of post-treatment evaluation was 6.12 years. To verify the influence of the severity of initial Class II molar relationship in stability of molar relationship, the sample was divided into two groups, one presenting a ½-cusp or ¾-cusp Class II molar relationship, and the other with full-cusp Class II molar relationship. In dental casts from initial, final and post-retention stages, molar, first and second premolars and canine relationships were measured. Data obtained were analyzed by dependent ANOVA, Tukey and Pearson's correlation tests, as well as independent t test between the two groups divided by severity of initial molar relationship. There was a non-statistically significant 0.12-mm relapse of molar relationship. The initial severity of Class II molar relationship was not correlated to relapse in the post-retention period. When compared, the two groups showed no difference in relapse of molar relationship. It was concluded that correction of Class II molar relationship is stable and initial severity does not influence relapse of molar relationship.

Efficacy of Nickel-Titanium Palatal Expanders

Objective: Timely treatment of narrow maxilla by means of maxillary expansion during the primary or transitional dentition is recommended to reestablish optimal function in order to normalize dental, skeletal and neuromuscular growth. The aim of this study was to assess the amount of orthodontic and orthopedic expansion achieved in the maxilla and to evaluate cephalometrically the various postural changes in the maxilla and mandible with the use of nickel-titanium palatal expander. Materials and methods: A total of ten subjects, five males and five females were selected from a survey conducted on 2000 children in age range of 7 to 15 years, belonging to various schools. Their study cast, cephalograms and occlusal radiographs were used for the study. Maxillary intermolar width, maxillary intercanine width and mandibular intermolar width were measured on study cast using Vernier caliper. Certain measurements were done on the cephalogram and occlusal radiograph. The data obtained out of various measurements made on study casts, frontal, lateral cephalograms and occlusal radiographs at the pretreatment, postexpansion and postretention stages were statistically analyzed. All the observations were made by two observers. The interexaminer variability was calculated using t-test. The mean and standard deviations were calculated and student's t-test (paired) was applied to determine the amount of change, variability of change and significance of change, respectively. Results: A constant force exerted by nickel-titanium palatal expander had orthopedic effects in growing age group indicated by statistically increase in the maxillary width. The ratio of relative orthodontic to orthopedic effect with this appliance was 6:1. Consequent to maxillary expansion, there occurred a significant downward movement of the maxillae and downward and backward rotation of the mandible. There was opening of midpalatal suture during active phase followed by suture remineralization during the retention period. Conclusion: To conclude, a Ni-Ti expander brings about expansion by a combination of orthodontic and orthopedic effects by an increase in maxillary intermolar, maxillary intercanine and mandibular intercanine widths as also the opening of the midpalatal suture.

Treatment stability in patients with Class II malocclusion treated with 2 maxillary premolar extractions or without extractions

The purpose of this study was to compare the occlusal stability of Class II malocclusion treatment with and without extraction of 2 maxillary premolars. A sample of 59 records from patients with complete Class II malocclusion was used. This sample was divided into 2 groups with the following characteristics: group 1, comprising 29 patients treated without extractions, and group 2, comprising 30 patients treated with extraction of 2 maxillary premolars. Dental cast measurements were obtained before and after treatment and at a minimum of 2.4 years after treatment. The pretreatment, posttreatment, and postretention occlusal statuses were evaluated with the peer assesment rating index. The occlusal indexes at the postretention stage and the posttreatment changes and percentages of posttreatment changes were compared with t tests. The nonextraction and the 2 maxillary premolar extraction treatment protocols of complete Class II malocclusions had no statistically significant differences in occlusal stability. Finishing Class II malocclusion treatment with the molars in a Class II relationship has similar occlusal stability as finishing with the molars in a Class I relationship.

Serial extraction of first premolars--postretention evaluation of stability and relapse.

Case records were evaluated for 30 patients who had undergone serial extraction of deciduous teeth plus first premolars followed by comprehensive orthodontic treatment and retention. Diagnostic records were available for the following stages: pre-extraction, start of active treatment, end of active treatment, and a minimum of 10 years postretention. All cases were treated with standard edgewise mechanics and were judged clinically satisfactory by the end of active treatment. Twenty-two of the 30 cases (73%) demonstrated clinically unsatisfactory mandibular anterior alignment postretention. Intercanine width and arch length decreased in 29 of the 30 cases by the postretention stage. There was no difference between the serial extraction sample and a matched sample extracted and treated after full eruption.

Influence of the quality of the finished occlusion on postretention occlusal relapse

In this study, we aimed to evaluate the influence of the quality of the finished occlusion on postretention occlusal stability. The sample comprised 87 patients with Class I malocclusion, treated with extraction of the 4 first premolars and edgewise mechanics; they were divided into 2 groups, according to the quality of their finished occlusions. Group 1 included 44 subjects (23 boys, 21 girls) with posttreatment peer assessment rating (PAR) scores from 0 to 5. The mean pretreatment age was 13.74 years (SD 2.14). The mean treatment time was 1.92 years (SD 0.57), the mean retention time was 1.75 years (SD 0.96), and the mean time of posttreatment evaluation was 5.17 years (SD 1.82). Group 2 included 43 subjects (22 boys, 21 girls) with posttreatment PAR scores greater than 5. The mean initial age was 13.34 years (SD 1.35). The mean treatment time was 2.20 years (SD 0.66), the mean retention time was 1.77 years (SD 0.78), and the mean posttreatment evaluation was 5.47 years (SD 1.60). The PAR and the Little irregularity indexes were measured on the dental casts at pretreatment, posttreatment, and postretention. Intergroup comparisons were made with independent t tests, and the Pearson correlation coefficient was applied to the PAR score for the whole sample at the times evaluated. Well-finished patients had lower posttreatment and postretention PAR scores and greater changes during the treatment and posttreatment periods than did the poorly finished patients. For the Little irregularity index, the only difference between the groups was at the posttreatment stage; group 1 had a smaller irregularity score than group 2. The correlation coefficients showed that the greater the treatment changes, the smaller the posttreatment PAR score and the greater the relapse. But the higher the posttreatment PAR score, the higher the postretention PAR score. It was concluded that the greater the quality of the orthodontic finished occlusion, the greater are the treatment changes and the amount of relapse and the better is the occlusal status at the postretention stage in Class I malocclusion treated with 4 premolar extractions.

Treatment stability with the eruption guidance appliance

Although the eruption guidance appliance has been used to correct Class II malocclusions for many years and its effects have been demonstrated, there is no study on the stability of the changes it produces. Therefore, the objective of this study was to investigate the long-term stability of cephalometric dentoskeletal and occlusal changes after eruption guidance appliance therapy. Thirty-nine patients were evaluated. Occlusal evaluations were made with the peer asseessment rating index, and anterior tooth irregularity was evaluated with the Little irregularity index. Cephalometric and occlusal data were obtained at pretreatment, posttreatment, and postretention. The data were analyzed by dependent 1-way analysis of variance (ANOVA) for comparison between the 3 stages of the experimental group, with the Newman-Keuls test as a second step. To compare the cephalometric experimental group changes with mean population changes, the t test was used. Cephalometrically, in the postretention stage, overjet remained stable, overbite showed significant relapse, and molar relationship improved toward a Class I relationship. The peer asseessment rating index showed stability of the occlusion. The Little irregularity index demonstrated a statistically significant relapse of crowding in the postretention stage. Cephalometrically, overjet and molar relationship were stable in the long term after treatment with the eruption guidance appliance; however, there was relapse of the overbite. Occlusally, correction of the malocclusion elevated by the peer assessment rating was stable. There was relapse of the anterior teeth crowding.

Estudo da recidiva da sobremordida relacionada com a curva de Spee, em pacientes Classe II, divisão 1, na fase pós-contenção

INTRODUÇÃO: a estabilidade dos resultados do tratamento ortodôntico é um assunto muito estudado na literatura, sem respostas conclusivas. A sobremordida, ou trespasse vertical, define-se como a relação vertical entre as bordas incisais dos incisivos superiores e inferiores, apresentando-se como um aspecto importante na avaliação dos resultados do tratamento e sua estabilidade. OBJETIVO: este estudo se propôs a avaliar a recidiva da sobremordida e sua relação com a curva de Spee. METODOLOGIA: a amostra (grupo experimental) constituiu-se de 29 pacientes, de ambos os gêneros, apresentando má oclusão de Classe II, divisão 1, e sobremordida mínima de 3,5mm, tratados com extração dos 4 primeiros pré-molares. Este grupo foi comparado a um grupo controle, com oclusão normal. A amostra faz parte do Arquivo da Disciplina de Ortodontia da FOB-USP. Avaliaram-se as telerradiografias em norma lateral e os modelos de estudo do início, final e 5 anos pós-tratamento e, para o grupo controle, as telerradiografias de dois tempos de avaliação, compatível com o tempo de tratamento do grupo experimental. Para comparação intergrupos, utilizou-se o teste t independente e, para comparação intragrupo, os testes ANOVA e Tukey. Para verificar a relação da recidiva da sobremordida com a curva de Spee, utilizou-se o coeficiente de correlação de Pearson. RESULTADOS: pela análise dos resultados obtidos, observou-se que a sobremordida apresentou uma correção significante durante o tratamento, comparando-se ao grupo controle. Porém, apresentou recidiva significante na fase pós-contenção. CONCLUSÃO: a recidiva da sobremordida apresentou uma correlação significante com a curva de Spee na fase pós-contenção.

Retrospective analysis of orthodontic treatment outcomes and its relation to postretention stability.

Objective:The present study was designed to retrospectively evaluate Class I malocclusion cases treated with extraction of the four first premolars, aiming to establish the relationship between the quality of orthodontic treatment outcomes and the long-term occlusal stability.Material and methods:The sample comprised 94 patients of both genders, presenting Class I malocclusion, treated with extractions of the four first premolars and Edgewise mechanics. All the patients selected were whites, being 50 males and 44 females. The mean pretreatment age was 13.46 years (s.d. 1.8). The mean treatment time was 2.09 years (s.d. 0.58), the mean retention time was 1.63 years (s.d. 0.73) and the mean time of postretention evaluation was 5.31 years (s.d. 1.61). The dental casts were measured at pretreatment (T1), posttreatment (T2) and postretention (T3), by the PAR index and by the Little irregularity index, and the correction due to treatment (T1-2) and the change at the postretention period (T3-2) were calculated. The descriptive statistics was performed and the Pearson correlation coefficient was applied for the PAR and the Little indices in the total sample, among the times evaluated.Results:The mean PAR reduction due to treatment was 78.54%, and 66.6%, at the postretention stage related to pretreatment stage. Significant correlations were found for the PAR index at the times evaluated, except between T1 and T2 and between T1-2 and T3. In other words, the higher the treatment correction (T1-2), the lower the posttreatment PAR index (PAR T2) will be, and the higher will be the PAR change at the postretention period (PAR T3-2). Also, the higher the posttreatment PAR score (PAR T2), the higher will be the postretention PAR score (PAR T3).Conclusion:It was concluded that the quality of orthodontic treatment outcomes is not related to the long-term occlusal stability.

Correlation between mandibular incisor crown morphologic index and postretention stability

Considering postretention stability as a result of successful orthodontic treatment, we aimed to verify the influence of mandibular-incisor-crown morphology in the relapse of mandibular anterior crowding. The sample comprised 56 white subjects of both sexes with Class I and Class II malocclusions at pretreatment, treated with extraction of 4 first premolars and edgewise mechanics. No patient underwent interproximal stripping during or after treatment. Mean pretreatment age was 13.23 years. Mean treatment time was 2.11 years, and mean posttreatment evaluation time was 5.12 years. Mandibular anterior crowding was measured with the Little irregularity index, and the mesiodistal and buccolingual proportion of the mandibular incisor crowns was measured with the Peck and Peck index. The measurements were obtained from dental casts at the pretreatment, posttreatment, and postretention stages. The Pearson correlation coefficient was calculated to determine the correlation between mandibular-incisor-crown morphology and the amount of postretention-crowding relapse. The mandibular-incisor-crown morphologic index was not significantly correlated with the amount of mandibular-anterior-crowding relapse. Mandibular-incisor-crown morphology is not correlated with the amount of mandibular-anterior-crowding relapse.

Long-term stability of anterior open bite extraction treatment in the permanent dentition

The purpose of this study was to cephalometrically evaluate the long-term stability of anterior open bite extraction treatment in the permanent dentition after a mean period of 8.35 years. Cephalometric headfilms were obtained at pretreatment, posttreatment, and postretention stages from 31 patients who had undergone orthodontic treatment with fixed appliances. Two control groups were used. The first, with an age similar to that of the experimental group before treatment, was used only to characterize it. The second, with normal occlusion, was followed longitudinally for a period comparable with the posttreatment period and was used to compare changes during this period. The differences between the observation stages in the experimental group were analyzed with paired t tests, and the posttreatment changes were compared with the changes of the second control group with independent t tests. There was no statistically significant decrease of the obtained anterior overbite at the end of the posttreatment period. The primary factors that contributed to the nonsignificant decrease of the overbite were the normal vertical development of the maxillary and mandibular incisors, the smaller vertical development of the mandibular molars, and the consequent smaller increase in lower anterior face height, as compared with the control group in the long-term posttreatment period. Additionally, 74.2% of the sample had a “clinically stable” open bite correction.

Stability of anterior open bite nonextraction treatment in the permanent dentition

This study cephalometrically evaluated the long-term stability of anterior open bite nonextraction treatment in the permanent dentition after a mean period of 5 years. The experimental group consisted of 21 patients who had undergone orthodontic treatment with fixed appliances from whom cephalometric headfilms were obtained at the pretreatment, posttreatment, and postretention stages. Two control groups were used. The first, with ages comparable with the experimental group before treatment, was used only to characterize it. The second control group, with normal occlusion, was longitudinally followed for a period comparable with the posttretention period and was used to compare the changes between groups during this period. The differences between the observation stages in the experimental group were analyzed with paired t tests, and the postretention changes were compared with the changes of the second control group with independent t tests. A statistically significant decrease of the obtained anterior overbite was demonstrated at the end of the postretention period. The primary factor that contributed to the overbite decrease was the smaller vertical development of the maxillary and mandibular incisors in the postretention period. Neither the pretreatment anterior open bite amount nor the magnitude of correction was associated with the long-term overbite decrease. However, 61.9% of the sample had a clinically stable open bite correction.

Stability of orthodontic treatment outcome: Follow-up until 10 years postretention

Dental casts of 1016 patients were evaluated for the long-term treatment outcome using the Peer Assessment Rating (PAR) index. The PAR index was measured at the pretreatment stage (n = 1016), directly posttreatment (n = 783), postretention (n = 942), 2 years postretention (n = 781), 5 years postretention (n = 821), and 10 years postretention (n = 564). The mean absolute change as well as the percentage of change per year (relapse) related to the postretention stage was calculated. An analysis of variance was applied to compare the mean change in the PAR between cases with and without a fixed retainer at the postretention stage and up to 10 years postretention. Drop-out analysis showed that more Class II Division 2 cases were lost to follow-up than cases of other Angle classes. The results indicate that 67% of the achieved orthodontic treatment result was maintained 10 years postretention. About half of the total relapse (as measured with the PAR index) takes place in the first 2 years after retention. All occlusal traits relapsed gradually over time but remained stable from 5 years postretention with the exception of the lower anterior contact point displacement, which showed a fast and continuous increase even exceeding the initial score. The presence of a fixed retainer had a positive effect on the PAR score. In cases with fixed retention, the relapse was 3.6 PAR points less at 5 years postretention and 4.6 points less at 10 years postretention. The results of this type of studies enable clinicians to inform their patients about treatment limitations in order to better meet their expectations. (Am J Orthod Dentofacial Orthop 1999;115:300-4)

Orthodontic treatment need prior to treatment and 5 years postretention.

To assess orthodontic treatment need prior to treatment and 5 years postretention in a large university sample. A random sample of 920 patients (400 male and 520 females) from the Department of Orthodontics and Oral Biology, University of Nijmegen, the Netherlands, were included in this study. Dental casts were evaluated using the Index of Orthodontic Treatment Need (IOTN) at the pretreatment (TP) and 5-year postretention stages (T5). The mean age at TP was 12.2+/-3.0 years and at T5 21.6+/-3.1 years. At TP and T5 the aesthetic component (AC) and the dental health component (DHC) were assessed. The difference between TP and T5 was compared for males and females and tested by the t-test. The changes in AC, DHC and treatment need categories were described at TP and at T5. On the basis of combined AC and DHC treatment need categories, 83% of the patients fell into the "Definite need" category prior to treatment and 10% of the treated patients were categorised as having "Definite need" 5 years postretention. No significant differences were found between males and females for the change in AC and DHC between TP and T5. The results indicate that the policy used in the department for patient selection gives priority to patients with a high treatment need. The results also provide a general impression of treatment outcome utilising the IOTN to analyse the change in the treatment need categories.

Chernoff Faces: An Orthodontic Application

This retrospective study examined 21 children (12 males and nine females) with Class III malocclusions, who had been successfully treated by a non-extraction technique and for whom follow-up records were available at least 2 years after all treatment and retention had ceased. On the basis of their post-retention records, children were divided into two groups: those who remained stable (n = 10) and those whose treatment relapsed (n = 11). A graphical technique of data description, Chernoff faces, in which variables for each individual may be portrayed by appropriate scaling of selected facial features, was used to construct cartoon faces for each child. Seven variables, overjet, overbite, upper and lower incisor inclination, the numbers of anterior and posterior teeth in lingual occlusion and the angle ANB were chosen and diagrammatic faces drawn using data from both the start of treatment and post-retention stages. These were arranged according to relapse status and scrutinized to determine whether the groups possessed any common features which were related to the outcome of treatment. The faces showed a wide range of variation, especially at the pretreatment stage. Whilst the cartoons were easy to read, no typical features could be identified at the start of treatment which might indicate that therapy would later relapse.

Long-term stability after orthodontic treatment: Nonextraction with prolonged retention

A sample of 22 previously treated orthodontic cases was studied to evaluate long-term stability. All cases were treated nonextraction with fixed edgewise appliances and were without retainers a minimum of 5 years. Data were obtained from study models, although 14 of the 22 cases had longitudinal cephalometric radiographs. The average retention time with a mandibular fixed lingual retainer was 8.4 years. The irregularity index pretreatment was 8.0 mm in the maxillary arch and 5.2 mm in the mandibular arch; at the end of treatment it was 0.9 mm and 1.0 mm, respectively, and at the postretention stage it was 2.0 mm and 2.4 mm, respectively. Resolution of the lower irregularity index was accomplished without incisor advancement or distal movement of the mandibular molar, however, both arches were expanded transversely. During the posttreatment stage all variables showed relapse except for the expanded maxillary canines and premolars. However, the mandibular anterior segment demonstrated relatively good alignment at the long-term stage, which may be a reflection of prolonged mandibular retention.

The Barry Project—a Three-Dimensional Assessment of Occlusal Treatment Change in a Consecutively Referred Sample: The Incisors

The serial occlusal changes for a consecutively referred sample of malocclusion from a Welsh town are presented. The patients were assigned to one of four treatment regimes (meant to represent those commonly used in the U.K.) and treated to a rigid protocol. Twenty-five per cent of the cases were reviewed by an eight clinician panel. No bias in the original assignments was found although there was considerable interobserver variation. At defined pretreatment, post-treatment, and post-retention stages, records were collected and the study casts quantitatively measured using a reflex metrograph and an occlusal analysis programme. The results found for the overjet, overbite, crown inclination, and crown angulation are presented and discussed.

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 irregularity 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.