Third Molar Comparison in Class I and II Extraction and Non-extraction Orthodontic Treatment: A Retrospective Longitudinal Study.

Objective: This study compared third molar angulation and eruption status in Class I and II malocclusions after orthodontic treatment with and without first premolar extractions. Methods: The sample comprised 93 patients divided into four groups: Group 1, Class I malocclusion treated with first premolar extractions; Group 2, Class I malocclusion treated without extractions; Group 3, Class II malocclusion treated with first premolar extractions; and Group 4, Class II malocclusion treated without extractions. Panoramic radiographs were used to evaluate the third molar mesiodistal angulations at T1 (pretreatment), T2 (posttreatment), and T3 (long-term posttreatment). Third molar eruption status was assessed in dental casts. Intergroup angulations and eruption status comparisons were performed using one-way analysis of variance (ANOVA), followed by Tukey's test and Kruskal-Wallis test, respectively. Results: Significantly greater mesial angulation and percentage of erupted right maxillary third molars were observed in the Class I extraction group. Significantly greater eruption status of the right mandibular third molars was observed in the Class I and Class II malocclusion extraction groups. Conclusion: Class I and II malocclusion extraction treatment exhibited more favorable angulations and a greater number of erupted third molars than non-extraction treatment. The non-extraction groups exhibited a greater percentage of unerupted third molars.

Effects of eruption guidance appliance in the early treatment of Class III malocclusion.

OBJECTIVES: To evaluate the dentoskeletal effects and effectiveness of the eruption guidance appliance in Class III patients in the mixed dentition. MATERIALS AND METHODS: The experimental group comprised 22 patients with Class III malocclusion and anterior cross-bite (12 males, 10 females, mean age 7.63 ± 0.96 years) treated with the eruption guidance appliance over a mean period of 1.72 ± 0.48 years. The control group comprised 22 untreated subjects (12 males, 10 females, mean age 7.21 ± 0.60 years) with Class III malocclusion. Lateral cephalometric radiographs were obtained at pretreatment (T1) and posttreatment (T2). Intergroup comparisons were performed with Mann-Whitney and t-tests (P < .05). RESULTS: In the experimental and control groups, the anteroposterior relationship between the maxilla and mandible (ANB angle) remained stable during the treatment period (T1 to T2). The mandibular plane angle decreased in the experimental group and increased in the control group. In the experimental group, the lower anterior face height increase and maxillary molar vertical development were significantly smaller compared to controls. Positive overjet was achieved in 54% of the experimental group. CONCLUSIONS: The eruption guidance appliance produced no change in the skeletal anteroposterior relationship. The anterior cross-bite/edge-to-edge relationship was corrected in only about half of the treated subjects.

Oral health-related quality of life, adaptation/discomfort during open bite treatment with spurs: complementary analysis from a randomized clinical trial.

This single-center trial aimed to longitudinally compare the oral health-related quality of life (OHRQOL), adaptation and discomfort during anterior open bite (AOB) treatment with lingual spurs and build-ups (SBU) versus spurs only (S) approaches. Children (7-11 years) with AOB were randomly allocated into two treatment groups (SBU or S). The Child Perception Questionnaire (CPQ8-10) was applied 1 and 12 months after installation of the appliances. Questionnaires evaluating functional adaptation and discomfort during the first month of treatment were also applied. A visual analog scale (VAS) was used in these questionnaires. Generalized mixed models were used for analyzing OHRQOL and discomfort data. Generalized linear models were used to assess adaptation outcomes (α = 0.05). The SBU group included 24 patients (7 males and 17 females; mean age 8.2 years) and the S group included 25 patients (11 males and 14 females; mean age 8.3 years). Regardless of the treatment type, overall OHRQOL scores at 12 months were 0.69 times those recorded at 1 month after the appliances installation (i.e., ~ 31% reduction; exp (ß) = 0.69; 95% CI: 0.55, 0.88). A significant interaction between treatment and time was detected for the 'functional limitations' domain. For this domain, a significant improvement from the first to the twelfth month was observed in the S group (P < 0.001). Patients in both treatment groups showed similar and easy adaptation to the appliances. Independent of the type of treatment, tongue-related discomfort decreased over time. One week and one month after the appliance's delivery, the discomfort scores were 0.19 (i.e., ~ 81% reduction; exp (ß) = 0.19; 95% CI: 0.13, 0.28; P < 0.001) and 0.02 (i.e., ~ 98% reduction; exp (ß) = 0.02; 95% CI: 0.01, 0.07; P < 0.001) times, respectively, those issued immediately after the installation of the appliances. Regardless of treatment type; overall OHRQOL improved from the first to the twelfth month of AOB treatment. The functional limitations score decreased in the S group. Children showed easy adaptation, and their discomfort decreased 1 week after the installation of the appliances.Trial registration: Clinicaltrials.gov; NCT03702881, date of registration: October 11, 2018.

Treatment stability with bonded versus vacuum-formed retainers after 12 months: A randomized clinical trial.

OBJECTIVE: To compare the clinical effectiveness of V-bend bonded retainers (BR) versus vacuum-formed retainers (VFR) regarding their capacity to maintain treatment stability and survival rates after 12 months. MATERIALS AND METHODS: Patients finishing orthodontic treatment were randomly allocated into two groups. The BR group received maxillary and mandibular BRs in the lingual surfaces of the anterior teeth. The VFR group received VFRs right after fixed appliances removal. The patients were evaluated at four time-points: at fixed appliances removal (T0), after 3 (T1), 6 (T2) and 12 months (T3). In each time-point digital models were obtained and analysed with the OrthoAnalyzer™ software. Treatment stability based on occlusal outcomes and retainers' survival rates were evaluated. Intergroup comparisons were performed using Mann-Whitney U-tests. The Kaplan-Meier survival plot and the log-rank test were employed to assess the retainers' survival. RESULTS: Both BR and VFR groups included 25 patients. The groups were comparable regarding their baseline characteristics. Up to 6 months, both retainers were equally effective; however, after 12 months, BRs were more effective in maintaining the incisors' alignment in the maxilla and the mandible compared to the VFRs. No differences were noticed in the intercanine and intermolar widths, overjet and overbite. There were no differences regarding the retainers' survivability in both arches. CONCLUSIONS: BRs were more effective in maintaining the alignment of the incisors in the maxilla and mandible compared to VFRs after 12 months. Both retainers presented the same survival rates after the same period.

Treatment of Class II malocclusion with 2-maxillary premolar extractions: Monthly vs biweekly appointments, which is more efficient?

INTRODUCTION: This study compared whether there is a difference in treatment time (TT) and efficiency when appointments are held once a month or at 2-week intervals in patients with Class II malocclusion treated with 2-premolar extractions METHODS: The patients of this retrospective sample were treated with the same orthodontic mechanics and divided into 2 groups according to frequencies of orthodontic appointments. Group 1 consisted of 18 patients (10 males, 8 females), with an initial mean age of 14.38 ± 1.38 years and appointments once a month. Group 2 consisted of 19 patients (9 males, 10 females), with an initial mean age of 14.12 ± 1.38 years and biweekly appointments. Edgewise fixed appliances with a slot size of 0.022 × 0.028 mm were used, and the anterior teeth were retracted en-masse with a rectangular wire and elastic chains. The Peer Assessment Rating and Objective Grading System indexes were measured in the dental models at the beginning and the end of treatment. Efficiency was assessed by dividing the percentage of improvement of each occlusal index concerning the multiplication of TT and the number of appointments. RESULTS: Both groups presented similar Peer Assessment Rating and Objective Grading System indexes at the end of treatment. Groups 1 and 2 presented different TTs (28.06 and 22.05 months, respectively); however, there were no differences regarding the efficiency of both protocols. CONCLUSIONS: Patients with Class II malocclusion treated with 2-maxillary premolars had significantly shorter treatment times when seen on biweekly appointments than those with monthly appointments; however, there was no difference in efficiency between protocols.

Erosive Tooth Wear in Subjects with Normal Occlusion: A Pioneering Longitudinal Study up to the Age of 60.

The aim of this study was to assess the erosive tooth wear (ETW) at early and mature adulthood in subjects with natural normal occlusion. The sample consisted of 23 untreated subjects with normal occlusion. Dental models were taken longitudinally from the same subjects at 13 (T0), 17 (T1) and 60.9 years of age (T2) at a university. Evaluation of ETW was performed using a modified Basic Erosive Wear Examination (BEWE) index. Interphase changes were evaluated using Friedman and Dunn's test. Ordinal logistic regression was used to assess the influence of sex, dental arch, tooth and dental surfaces on the erosive tooth wear. Linear regression was used to evaluate whether the ETW degree at T1 could discriminate the degree of ETW at T2. The significance level adopted was 5%. ETW showed a significant increase with aging. The median ETW index at T0, T1 and T2 was 2, 4 and 7, respectively. ETW was greater in males in the incisors and canines and on the incisal/occlusal and lingual tooth surfaces. No significant differences were found between the maxillary and mandibular arches. Subjects with severe ETW at mature adulthood had greater tooth wear at age 17. In conclusion, ETW significantly increased during aging in subjects with normal occlusion. The greater the degree of tooth wear at early adulthood, the greater the tooth wear at mature adulthood. Preventive care should be recommended during early adulthood in patients demonstrating erosive tooth wear in order to avoid worsening with aging.

Incisors' bone height and inclination changes after orthodontic treatment with a self-ligating passive system.

Background: This study aimed to evaluate changes in the alveolar buccal bone height of maxillary and mandibular incisors after orthodontic treatment with a self-ligating passive system and to assess the correlation between bone height and incisor inclination. Material and Methods: Pre (T1) and post-treatment (T2) cone-beam computed tomography images of patients treated with the Damon 3MX appliance system were measured to quantify the alveolar buccal bone height of the maxillary incisors. The incisor's inclination was measured in digital models. Paired t-test was used to evaluate the changes between T1 and T2, and Pearson's coefficient was used to test the correlation. Results: All teeth presented statistically significant alveolar buccal bone loss at T2. A statistically significant buccal inclination was observed only for the lower left lateral incisors. There was no correlation between bone height changes and incisor inclination. Conclusions: Orthodontic treatment with a self-ligating passive system showed changes in alveolar height, but these changes were not correlated with incisor inclination. Key words:Passive self-ligating brackets, orthodontics, corrective, treatment outcome, alveolar bone loss.

Finite element analysis of two skeletally anchored maxillary molar distalisation methods.

OBJECTIVE: To compare two methods of maxillary molar distalisation with skeletal anchorage using finite element analysis (FEA). METHODS: Two digitised models were created: the miniscrew-anchored distaliser, which consisted of a distalisation method anchored in a buccal miniscrew between the first molar and second premolar (Model 1), and the miniscrew-anchored palatal appliance, which consisted of a distalisation method anchored in a miniscrew on the anterior region of the palate (Model 2). FEA was used to simulate both methods, assessing teeth displacements and stress concentration. RESULTS: The miniscrew-anchored distaliser showed greater buccal than distal displacement of the first molar, while the opposite was observed in the miniscrew-anchored palatal appliance. The second molar responded similarly in the transverse and anteroposterior perspectives with both appliances. Greater displacements were observed at crown level than in apical regions. Greater stress concentration was observed at the buccal and cervical regions of the crown in the miniscrew-anchored distaliser and the palatal and cervical regions in the palatal appliance. The stress progressively spread in the buccal side of the alveolar bone for the miniscrew-anchored distaliser and in the palatal root and alveolar bone for the palatal appliance. CONCLUSION: FEA assumes that both appliances would promote maxillary molar distalisation. A skeletally anchored palatal distalisation force seems to provide a greater molar bodily movement with less undesirable effects. Greater stress is expected at the crown and cervical regions during distalisation, and the stress concentration in the roots and alveolar bone depends directly on the region the force was applied.

Three-dimensional changes after maxillary molar distalization with a miniscrew-anchored cantilever.

OBJECTIVES: To evaluate the changes after maxillary molar distalization in Class II malocclusion using the miniscrew-anchored cantilever with an extension arm. MATERIALS AND METHODS: The sample included 20 patients (9 male, 11 female; mean age 13.21 ± 1.54 years) with Class II malocclusion, treated with the miniscrew-anchored cantilever. Lateral cephalograms and dental models obtained before (T1) and after molar distalization (T2) were evaluated using Dolphin software and 3D Slicer. Superimposition of digital dental models using regions of interest on the palate was performed to evaluate three-dimensional displacement of maxillary teeth. Intragroup change comparisons were performed using dependent t-test and Wilcoxon test (P < 0.05). RESULTS: The maxillary first molars were distalized to overcorrected Class I. The mean distalization time was 0.43 ± 0.13 years. Cephalometric analysis demonstrated significant distal movement of the maxillary first premolar (-1.21 mm, 95% confidence interval [CI]: -0.45, -1.96) and maxillary first (-3.38 mm, 95% CI: -2.88, -3.87) and second molars (-2.12 mm, 95% CI: -1.53, -2.71). Distal movements increased progressively from the incisors to the molars. The first molar showed small intrusion (-0.72 mm, 95% CI: 0.49, -1.34). In the digital model analysis, the first and second molars showed a crown distal rotation of 19.31° ± 5.71° and 10.17° ± 3.84°, respectively. The increase in maxillary intermolar distance, evaluated at the mesiobuccal cusps, was 2.63 ± 1.56 mm. CONCLUSIONS: The miniscrew-anchored cantilever was effective for maxillary molar distalization. Sagittal, lateral, and vertical movements were observed for all maxillary teeth. Distal movement was progressively greater from anterior to posterior teeth.

Incisor irregularity and dental arch dimensions changes in subjects with different severity of anterior crowding: a 37-year follow-up.

BACKGROUND: Occlusal stability is one of the goals of orthodontic treatment, and keeping teeth aligned in the long term is a challenge for the orthodontist. This study aimed to compare the long-term incisors irregularity and dental arches dimensions changes in subjects treated with 4 premolar extractions with different pretreatment Little's irregularity index (LII). The knowledge of long-term outcomes is evidence-based information for the prognosis of future treatments. METHODS: In total, 41 treated subjects were divided into two groups according to mandibular Little irregularity value at pretreatment (mild or severe). The maxillary and mandibular LII, transversal, and longitudinal widths were assessed at pretreatment, posttreatment, and 37-year posttreatment. Chi-square and independent t tests were used for intergroup comparison. RESULTS: The groups presented similar behavior for all stages of maxillary and mandibular arch dimensions changes. Maxillary irregularity was corrected in both groups after treatment, and the alignment was acceptable in the long term. In the mild group, the mandibular incisor irregularity returned to pretreatment values in the long term. The mandibular LII increased in the severe group but did not return to pretreatment values in the long term. CONCLUSIONS: The mild crowding group presented proportionally more relapse of mandibular incisor irregularity than the severe crowding group in the long term. Even so, the correction of mild and severe crowding with the extraction of 4 premolars showed satisfactory results in the long term, even with the presence of maturational changes and relapse.

Treatment effects of the MARA appliance and Activator-Headgear combined with fixed appliances in Class II division 1 malocclusion patients: A retrospective longitudinal study.

INTRODUCTION: Class II division 1 malocclusion treatment with functional devices offers acceptable results. These devices can be removable or fixed, and the essential difference between them is the need for compliance. It is clinically important to investigate if there are differences in the treatment effects of these devices that present different characteristics. OBJECTIVE: This retrospective longitudinal study compared the treatment effects of Class II correction with the MARA appliance, Activator-Headgear (AcHg) combination, both followed by multibracket fixed appliances, and an untreated control group. MATERIAL AND METHODS: Each experimental group was composed of 18 patients, with a baseline mean age of 11.70 and 10.88 years, treated for 3.60 and 3.17 years. The control group consisted of 20 subjects with baseline mean age of 11.07 years. The groups were evaluated before (T1) and after (T2) treatment. Lateral radiographs were used to evaluate the treatment changes with treatment (T2-T1), compared to the control group. Intergroup comparisons were performed using repeated-measures analysis of variance (ANOVA), followed by Tukey's test. RESULTS: The AcHg group showed significantly greater maxillary growth restriction than the MARA, while the mandibular changes were due to natural growth. Both devices promoted significantly greater maxillary incisors retrusion, mandibular incisors labial inclination, and improvement of overjet and molar relationships, compared to the control. CONCLUSIONS: Both functional devices followed by multibracket appliances were effective to correct Class II malocclusion. Nonetheless, the AcHg combination presents superior skeletal effects, due to significantly greater maxillary growth restriction compared to the MARA appliance. Moreover, the appliances presented similar dentoalveolar effects.

Psychological and financial impact of the COVID-19 pandemic during the first stages of the pandemic: Brazilian orthodontists´ perspective.

INTRODUCTION: Brazil faced a catastrophic situation in the coronavirus pandemic. Due to the high risk of contamination and spread of COVID-19, dentist have been attending only urgency and emergency services in Brazil at the beginning of the pandemic. OBJECTIVE: This research aimed to evaluate the psychological and financial impacts caused by the coronavirus pandemic in Brazilian orthodontists. METHODS: This population-based cross-sectional study collected demographic data and mental health measurements from 404 orthodontists. Depression, anxiety, insomnia, and distress were evaluated through Brazilian versions of the 9-item Patient Health Questionnaire (9-PHQ), the 7-item Generalized Anxiety Disorder scale and Mini-Tracking (GAD), the 7-item Insomnia Severity Index (ISI), and the 22-item Impact of Event Scale-Revised (IES-R), respectively. The demographic data of the sample was described using descriptive statistics. The data was analyzed according to sex, professional status, and economic income. Comparisons were performed using Chi-square tests, Mann-Whitney U tests, and Kruskal-Wallis followed by post-hoc tests. RESULTS: Females, graduate students, and lower incomes subgroups showed higher levels of depression, anxiety, insomnia, and distress. Most orthodontists showed moderate to extreme financial and professional concerns during the pandemic. CONCLUSION: The coronavirus pandemic negatively affected the psychological health and increased the financial concerns of the Brazilian orthodontists, mainly female, graduate students, and with income below 10k participants.

Stability of Class II malocclusion treatment with Class II elastics.

INTRODUCTION: The objective of this study was to compare the long-term cephalometric stability after successful therapy of nonextraction Class II malocclusion with elastics and with headgear. METHODS: The sample comprised 43 patients with Class II malocclusion and was divided into 2 groups. The elastic group (EG) consisted of 20 patients treated with fixed appliances associated with Class II elastics, and the headgear group (HG) consisted of 23 patients treated with fixed appliances and extraoral headgear. Pretreatment, posttreatment, and long-term posttreatment lateral radiographs were evaluated; t tests were used to compare the long-term posttreatment changes between the groups. RESULTS: The groups were matched regarding initial age, time of long-term posttreatment evaluation, initial malocclusion severity, quality of treatment result, and all pretreatment cephalometric variables. Intergroup comparisons of long-term posttreatment changes showed that the HG group presented significantly greater mandibular protrusion, occlusal plane angle decrease, and maxillary molar mesialization. However, long-term posttreatment stability was similar in overjet, overbite, and molar relationships. CONCLUSIONS: Nonextraction Class II malocclusion treatment with elastics or extraoral headgear have similar long-term posttreatment stability.

Longitudinal behavior of orthodontic extraction spaces: A retrospective dental cast analysis.

INTRODUCTION: This retrospective study aimed to qualitatively and quantitatively evaluate orthodontic extraction space behavior and size at the end of treatment and the short- and long-term stages in Class I, II, and III malocclusions. METHODS: The sample comprised records of 1283 orthodontic patients treated with extractions (cross-sectional group). From these patients, 1- and 5-year posttreatment records of 214 patients were additionally evaluated (longitudinal group). Orthodontic extraction sites of immediate (end of treatment), short-term (1-year posttreatment), and long-term (5-year posttreatment) stage dental casts were measured with a digital caliper. Extraction spaces were classified according to their qualitative behavior in the open, closed, reopened, and recently closed spaces. Space qualitative longitudinal behavior was compared among the malocclusion types with chi-square tests. Kolmogorov-Smirnov normality tests were performed to check the variable's distribution. All variables showed normal distribution, except the malocclusion group ages. Therefore, parametric tests were used for all comparisons between the malocclusion groups, except for age comparisons in each stage, which were compared with the Kruskal-Wallis tests. Thus, space size and its reduction were compared among the 3 stages, in general, and between the maxillary and mandibular arches, with analysis of variance followed by Tukey tests and t tests, respectively. RESULTS: Classes I, II, and III malocclusion patients presented similar ages at each stage. At the end of treatment, 71.4% and 65.1% of the quadrants were closed in the cross-sectional and longitudinal groups, respectively, and 43.6% and 38.2% of patients presented all quadrants closed at this same stage in both groups. The reopening and late closure tendencies were 2.9 and 2.3 times greater in the short term than in the long term. Reopening tendency in the short-term was greater in Class II than in Class I malocclusion. Of the quadrants closed at the end of treatment, 87% were stable in the long term. From the quadrants with residual spaces at the end of treatment, 28.4% persisted openly in the long term. Residual space size reduced significantly in the short and long term, primarily in the mandibular arch. CONCLUSIONS: The percentage of patients with residual spaces at the end of treatment was 56.4%. Space reopening and late closure occur mainly in the first year after treatment. There was long-term stability in 87% of the quadrants closed at the end of treatment. There was a significant reduction in orthodontic extraction space size in the short and long term, especially in the mandibular arch.

Mandibular asymmetry retreatment with minimal presurgical orthodontic preparation and fully customized lingual orthodontics: A case report with new possibilities using blender open-source software.

New possibilities such as Surgery-first and Minimal Presurgical Orthodontics have become extra alternatives for patients, orthodontists, and oral and maxillofacial surgeons, with immediate facial improvements, reduced preparation time, and shorter treatment time. The purpose of this case report was to demonstrate the retreatment of a female patient, dissatisfied with the instability of the compensatory orthodontic treatment, chin deviation, and forward inclination of the maxillary incisors, which was successfully treated with Minimal Presurgical Orthodontic approach associated with customized lingual brackets and virtual planning on the open-source Blender 3D software, where the post-surgical maxillary lingual brackets were also designed. Orthodontic preparation was performed in 5 months. After surgery, orthodontic treatment was finished with the aid of mini-implants and miniplates. The total treatment time was 18 months. Great facial and occlusal results were obtained and the patient was satisfied. Overall, all treatment steps were performed following a digital workflow and open-source software. It is possible to conclude that Minimal Presurgical Orthodontic Preparation was an excellent alternative for the retreatment of this patient with mandibular asymmetry and increased treatment expectations. Additionally, the surgical planning and design of lingual braces with open-source software can be considered useful and low-cost alternatives for orthodontists.

Root resorption in Class II malocclusion treatment with and without maxillary premolar extractions.

INTRODUCTION: Class II malocclusion treatment efficiency with maxillary premolar extractions has been reported. However, no study evaluated the root resorption associated with this protocol. Therefore, this study aimed to compare the degree of root resorption of the maxillary incisors in Class II malocclusion treatment with and without maxillary premolar extractions. METHODS: The sample consisted of 56 patients with complete Class II malocclusion, divided into 2 groups. Group 1 comprised 28 patients (10 female, 18 male) treated with maxillary first premolar extractions, and group 2 was composed of 28 patients (16 female, 12 male) treated without extractions. The groups were matched regarding initial age, treatment time, crowding, initial malocclusion severity, finishing quality, initial overjet, and overbite. Periapical radiographs of the maxillary incisors were used to assess the degree of root resorption using a scoring system. In addition, treatment changes involving maxillary incisors were evaluated in lateral headfilms. Intergroup comparisons were performed with t, Mann-Whitney U, and chi-square tests (P <0.05). RESULTS: Overjet, overbite, inclination, vertical positional changes, and vertical and horizontal apical displacements of maxillary incisors were similar between groups. There was no statistically significant difference between groups regarding root resorption of maxillary incisors. Root resorption degree ranged from mild to moderate in both groups. CONCLUSIONS: Treating complete Class II malocclusion with 2 maxillary premolar extractions resulted in a similar root resorption as treating without maxillary premolar extractions. An individualized evaluation of root resorption predisposing factors should be performed for each patient.

Comparison between clear aligners and 2 × 4 mechanics in the mixed dentition: a randomized clinical trial.

OBJECTIVES: To compare the efficacy and efficiency between clear aligners and 2 × 4 fixed appliances for correcting maxillary incisor position irregularities in the mixed dentition. MATERIALS AND METHODS: The sample comprised 32 patients from 7 to 11 years of age randomly allocated into two parallel treatment groups: the clear aligners group, 14 patients (6 girls, 8 boys) with a mean initial age of 9.33 years (standard deviation [SD] = 1.01) treated with clear aligners; and the fixed appliances group, 13 patients (9 girls, 4 boys) with a mean initial age of 9.65 years (SD = 0.80) treated with partial (2 × 4) fixed appliances. Digital models were acquired before treatment and after appliance removal. Primary outcomes were incisor irregularity index and treatment time. Secondary outcomes were arch width, perimeter, length, size and shape, incisor leveling, incisor mesiodistal angulation, plaque index, and white spot lesion formation (International Caries Detection and Assessment System index). Intergroup comparisons were evaluated using t-tests or Mann-Whitney U-tests with Holm-Bonferroni correction (P < .05). RESULTS: Treatment time was approximately 8 months in both groups. No intergroup differences were observed for changes in any of the variables. Similar posttreatment arch shapes were observed in both groups. CONCLUSIONS: Clear aligners and 2 × 4 mechanics displayed similar efficacy and efficiency for maxillary incisor position corrections in the mixed dentition. The choice of appliance should be guided by clinician and family preference.