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.

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.

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.

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.

Twin-block and mandibular anterior repositioning appliances effects in Class II malocclusion correction.

INTRODUCTION: The objective of this study was to compare the cephalometric changes in Class II Division 1 malocclusion patients treated with the Twin-block (TB) and the mandibular anterior repositioning appliance (MARA). METHODS: This retrospective study was performed with 132 lateral cephalograms of patients with Class II malocclusion divided into 3 groups: a TB group comprised 21 patients with mean initial and final ages of 10.59 and 11.97 years, respectively, treated for a mean period of 1.38 years; a MARA group comprised 21 patients with mean initial and final ages of 11.98 and 13.20 years, respectively, treated for a mean period of 1.22 years; and a control group included 24 subjects with untreated Class II malocclusion with mean initial and final ages of 10.55 and 12.01 years, respectively, observed for a mean period of 1.46 years. Cephalometric intergroup comparisons regarding the treatment changes (T2 - T1) were performed with the analysis of covariance, followed by Tukey tests. RESULTS: Both appliances demonstrated significant restriction of the maxilla and improvement of the maxillomandibular relationship. The MARA produced a significantly greater amount of labial tipping and protrusion of the mandibular incisors than the other groups. The TB showed significant extrusion of the mandibular incisors and molars compared with MARA and control, respectively. Both treated groups reduced the overjet and overbite. The MARA presented a significantly greater reduction in the molar relationship than the other groups. CONCLUSIONS: The appliances showed a headgear effect on the maxilla and effectively changed Class II cephalometric parameters through a combination of skeletal and dentoalveolar effects. TB showed a greater increase in LAFH. MARA promoted greater labial tipping and protrusion of the mandibular incisors.

Dentoskeletal and soft-tissue changes of class II malocclusion treatment with modified first class appliances: a prospective clinical trial.

BACKGROUND/OBJECTIVES: Intraoral distalizers are effective and conservative alternatives for Class II malocclusion treatment. However, the literature is still controversial regarding the effects of using skeletal anchorage in intraoral distalizers with different designs. The aim of this study is to compare dentoskeletal and soft-tissue changes of Class II malocclusion patients treated with three types of First Class (FC) distalizers. MATERIALS/METHODS: The sample of this prospective clinical trial included 30 consecutive patients divided into three groups: G1-FC conventionally anchored; G2-FC skeletally anchored Type 1; G3-FC skeletally anchored Type 2. Each group consisted of 10 patients. Lateral cephalograms were analyzed in two stages: at pre-treatment (T0) and after distalization (T1). The radiographs were digitized and analyzed using the software Dolphin Imaging 11.5. Comparisons of treatment changes between groups (T1-T0) were performed using one-way analysis of variance (ANOVA), followed by the Tukey test. RESULTS: Patients treated with the conventionally anchored FC showed significantly greater incisors protrusion and labial inclination, second premolars mesial inclination and mesialization than the FCs skeletally anchored. No differences were observed regarding the amount of molar distalization and molar angulation between groups. LIMITATIONS: It can be considered that the limitation of this study lies in its non-randomized design. CONCLUSIONS/IMPLICATIONS: First Class distalizers with conventional and skeletal anchorage are effective alternatives for Class II molar distalization. Distalization associated with indirect skeletal anchorage reduce the undesirable effects observed in the incisors and premolars during distalization when compared to distalization conventionally anchored.

Effects of the Forsus fatigue-resistant device and mandibular anterior repositioning appliance in Class II malocclusion treatment.

INTRODUCTION: Fixed functional appliances have been used to treat Class II malocclusion by a huge number of professionals. This retrospective study aimed to analyze the effects of the Forsus fatigue-resistant device and compare the findings with a well-matched group treated with the mandibular anterior repositioning appliance (MARA). METHODS: The Forsus group was composed of 14 patients at an initial mean age of 12.4 ± 1.3 years, treated with the Forsus fatigue-resistant device followed by a fixed orthodontic appliance. The MARA group comprised 18 patients at an initial mean age of 12.1 ± 1.3 years, treated with MARA followed by fixed orthodontic appliances. The untreated control group consisted of 14 patients matched with the other groups. Posttreatment changes were calculated as T1 - T2. Intergroup comparisons regarding treatment changes were performed using repeated-measures analysis of variance followed by Tukey's test. RESULTS: During treatment, the Forsus group showed a statistically significant decrease in maxillary protrusion and maxillomandibular sagittal discrepancy in the control group. The MARA group showed significantly greater retrusion of maxillary incisors than the Forsus and the control group. Overjet decreased significantly more in the treated groups in relation to the control group. Molar relationship improved significantly more in both treated groups, and both showed more correction than the untreated control group. CONCLUSIONS: The Forsus and MARA associated with fixed appliances effectively corrected the Class II malocclusion, mostly using dentoalveolar changes and maxillary growth restriction.

Long-term stability of Class II malocclusion treatment with the cantilever bite jumper.

INTRODUCTION: This study aimed to assess the long-term stability of Class II malocclusion treatment with the Cantilever Bite Jumper (CBJ) after 13 years of follow-up. METHODS: The treatment group comprised 10 Class II Division 1 malocclusion patients treated with the CBJ, followed by fixed appliances, analyzed at 3 stages: pretreatment (aged 11.56-14.32 years), posttreatment (aged 16.34-19.58 years), and long-term posttreatment (aged 29.04-32.33 years). The control group included 15 subjects with normal occlusion. Intragroup treatment changes comparison was performed with repeated measures and analysis of variance followed by Tukey tests. Intergroup comparisons regarding the long-term posttreatment changes were performed with t tests. RESULTS: No statistically significant relapse was observed during the follow-up period. Morever, the treated group presented a significantly smaller increase in lower anterior facial height and greater retrusion of the lower lip than the control group in the posttreatment period. CONCLUSIONS: Treatment with the CBJ, followed by fixed appliances, is a stable alternative for Class II Division 1 malocclusion correction. The dentoskeletal and soft-tissue changes obtained during treatment remained stable in the long-term posttreatment follow-up.

Treatment stability with bonded versus vacuum-formed retainers: a systematic review of randomized clinical trials.

BACKGROUND: In orthodontics, the retention phase can be considered challenging and unpredictable. Therefore, evidence obtained from different retention protocols is important to facilitate clinical decision-making. OBJECTIVES: This systematic review aimed to compare the clinical effectiveness of bonded versus vacuum-formed retainers (VFRs) regarding their capacity to maintain treatment stability, periodontal effects, and failure rates. SEARCH METHODS AND ELIGIBILITY CRITERIA: Ten databases comprising published and unpublished literature were systematically searched up to August 2021. Randomized clinical trials (RCTs) comparing both retainers were included. DATA COLLECTION AND ANALYSIS: The risk of bias (RoB) evaluation was performed with the Cochrane Collaboration RoB Tool 2.0. All steps of the screening phase and RoB assessment were performed independently by two reviewers. The Grade of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to evaluate the certainty of the evidence. RESULTS: Initial database search yielded 923 studies. After duplicates removal and full-text assessment, five RCTs remained. Overall, the studies presented Low RoB, except one study judged with 'Some concerns'. Based on the included studies, on a short-term (3-6 months) and long-term (4 years) basis, bonded retainers (BRs) were more effective to maintain treatment stability than VFRs in the lower arch. However, from 12 to 24 months both retainers presented the same efficacy. In the upper arch, the retainers were equally effective. BRs were associated with greater plaque and calculus accumulation than VFRs after 12 months. The retainers' failure rates were similar in the upper arch on the first year of retention; however, after 2 years VFRs showed significantly greater failure rates. Contrarily, BRs presented greater failure rates in the lower arch than VFRs. LIMITATIONS: The findings of the included studies may be influenced by different factors related to the unpredictability of relapse. CONCLUSIONS: Most of the evidence generated in this systematic review derived from a moderate level of certainty. In the lower arch, BRs are more effective than VFRs to maintain treatment stability in the initial 6 months of retention and in the long term. In the upper arch, both retention protocols are equally effective. REGISTRATION: Regist0ration number: PROSPERO CRD42020199392. FUNDING: Coordination for the Improvement of Higher Educational Personnel (CAPES, Process code-001).

Class II treatment effects with fixed functional appliances: Jasper jumper vs. Forsus fatigue resistant device.

OBJECTIVE: This study aimed to compare cephalometric changes of Class II malocclusion patients treated with Jasper Jumper and Forsus, associated with fixed appliances. METHODS: The sample consisted of 62 individuals divided into 3 groups: group 1 included 22 subjects with a mean initial age of 12.39 years, treated with Jasper Jumper associated with fixed appliances for a mean period of 2.43 years; group 2 included 19 subjects with a mean initial age of 12.43 years, treated with Forsus associated with fixed appliances for a mean period of 3.54 years; and group 3 included 22 Class II malocclusion untreated subjects at a mean age of 12.14 years, followed for a mean period of 1.78 years. Intergroup comparison was performed with one-way ANOVA, followed by Tukey test. RESULTS: Both treated groups had similar dentoskeletal changes: restrictive effect on the maxilla; clockwise rotation of the occlusal plane; mild increase in lower anterior facial height; limitation on the vertical development of the maxillary molars; labial tipping and intrusion of the mandibular incisors; extrusion of mandibular molars; improvements of the maxillomandibular relationship, overjet, overbite, molar relationship; and retrusion of the upper lip. The mandibular incisors exhibited greater protrusion in group 1 compared to the other groups. In addition, group 2 presented mild protrusion of the lower lip, and groups 1 and 3 showed mild retrusion. CONCLUSION: The Jasper Jumper and Forsus appliances were effective and showed similar changes in the treatment of Class II malocclusion.

Mesioangulation of mandibular second molars: A case report.

This case report describes a simple alternative for treatment of mesioangulation of mandibular second molars. An 11-year-old girl was diagnosed with unilateral posterior crossbite, moderate incisor crowding and mesioangulation of the right mandibular second molar. The ectopic second molar was uprighted using a modified lingual arch with a distal hook and elastic chains. Orthodontic traction began after appliance installation and was activated once per month using 120 g of force. After six months, the right mandibular second molar was in an upright position. Orthodontic treatment continued with teeth levelling and alignment until acceptable occlusal and aesthetic results were achieved. Adequate stability was observed one year after debonding. The modified mandibular lingual arch with a distal hook is a simple and effective alternative to manage mesioangulation of mandibular second molars with minimum adverse effects and stable outcomes.

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

ABSTRACT 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.

RESUMO Introdução: O tratamento da má oclusão de Classe II divisão 1 com dispositivos funcionais oferece resultados aceitáveis. Esses dispositivos podem ser removíveis ou fixos, e a diferença essencial entre eles é a necessidade de colaboração. É clinicamente importante investigar se existem diferenças nos efeitos do tratamento desses dispositivos que apresentam características diferentes. Objetivo: O presente estudo retrospectivo longitudinal comparou os efeitos do MARA e da combinação Aparelho Extrabucal-Ativador (AEB-At) no tratamento da Classe II, ambos seguidos por aparelho fixo, adicionando também um grupo controle não tratado. Métodos: Cada grupo experimental foi composto por 18 pacientes; respectivamente, com média de idade inicial de 11,70 e 10,88 anos, tratados por 3,60 e 3,17 anos. O grupo controle foi composto por 20 indivíduos, com idade média inicial de 11,07 anos. Os grupos foram avaliados antes (T1) e após (T2) o tratamento. Radiografias de perfil foram utilizadas para avaliar as alterações do tratamento (T2-T1), em comparação com o grupo controle. As comparações intergrupos foram realizadas por meio da análise de variância para medidas repetidas (ANOVA), seguida pelo teste de Tukey. Resultados: O AEB-At apresentou uma restrição do crescimento maxilar significativamente maior que o MARA, enquanto as alterações mandibulares foram decorrentes do crescimento natural. Ambos os dispositivos promoveram significativamente mais retrusão dos incisivos superiores, inclinação vestibular dos incisivos inferiores e melhora da sobressaliência e relação molar, em comparação com o controle. Conclusões: Ambos os dispositivos funcionais associados ao aparelho fixo foram efetivos na correção da má oclusão de Classe II. No entanto, a combinação AEB-At apresenta efeitos esqueléticos superiores, devido à restrição de crescimento maxilar significativamente maior do que com o aparelho MARA. Além disso, os aparelhos apresentaram efeitos dentoalveolares semelhantes.

Retrospective comparison of dental and skeletal effects in the treatment of Class II malocclusion between Herbst and Xbow appliances.

INTRODUCTION: The purpose of this research was to compare dentoskeletal changes produced by Herbst and Xbow appliances in late mixed/early permanent dentition patients with Class II Division 1 malocclusion to an untreated control group. METHODS: The retrospective cohort consisted of 41 patients treated with the Herbst appliance on average for 14 months (mean age of 11.3 years), 41 patients treated with Xbow appliance on average for 14 months (mean age of 11.11 years), and an untreated control sample of 25 patients followed on average for 21 months (mean age of 11.9 years). All patients had Class II Division 1 malocclusion characteristics. Lateral cephalometric radiographs were taken before and after phase 1 treatment/follow-up. Data were analyzed by an analysis of variance followed by Tukey post-hoc tests. RESULTS: Although there was a high equivalence among the groups in the pretreatment cephalometric values, 4 variables showed differences (U6-FHp, L6-FHp, LAFH, and PP-U1). When comparing the mean changes (before and after phase 1 treatment/follow-up), incisor mandibular plane angle (IMPA), Wits appraisal, L6-FHp, Co-Pog, and PP-U1 measurements showed statistically significant differences. In addition, more relative mesial movement of the mandibular molars (an additional 2.4 mm) and a larger increase in mandibular length (an additional 3.2 mm) was noted for the Herbst group. CONCLUSIONS: Class II correction using Herbst and Xbow occurred in both groups through improvement in the maxillomandibular relationship and labial inclination of the mandibular incisors, as well as a relatively increased mesialization of the mandibular molars. Although both appliances improve occlusal features, the portrayed changes were not always similar. Herbst seems to produce more mandibular size increase over a similar treatment period.

Sagittal, rotational and transverse changes with three intraoral distalization force systems: Jones jig, distal jet and first class.

BACKGROUND: To compare the maxillary dentoalveolar changes of patients treated with three distalization force systems: Jones Jig, Distal Jet and First Class appliances, using digitized models. MATERIAL AND METHODS: The retrospective sample comprised 118 digitized models of 59 patients with Class II malocclusion divided into three groups: Group 1 consisted of 22 patients treated with the Jones Jig appliance; Group 2 consisted of 20 patients treated with the Distal Jet, and Group 3 comprised 17 patients treated with the First Class appliance. Pretreatment and post-distalization plaster models of all patients were digitized and evaluated with OrthoAnalyzerTM software. The pretreatment and post-distalization variables regarding sagittal, rotational and transverse changes were compared by the One-way Analysis of Variance (ANOVA) and Kruskal-Wallis tests, depending on normality. RESULTS: All appliances presented similar amounts of distalization. The Distal Jet appliance promoted significantly smaller mesial displacement of premolars and greater expansion of posterior teeth. The First Class presented the smallest rotation of the maxillary molars and treatment time. CONCLUSIONS: The distalizers were effective in correcting Class II molar relationship, however, a palatal force seems to provide fewer undesirable effects. Additionally, the degree of rotation and expansion was associated with the side of force application. Key words:Malocclusion, Angle Class II, Orthodontics, Corrective, Distalizers.

Evaluation of root resorption following orthodontic intrusion: a systematic review and meta-analysis.

BACKGROUND/OBJECTIVE: To quantify the expected amount of orthodontically induced root resorption (OIRR) after orthodontic intrusion and assess the treatment-related factors. SEARCH METHODS AND ELIGIBILITY CRITERIA: Six electronic databases and partial grey literature were searched without limitations regarding language or publication year until April 2020. Randomized clinical trials and non-randomized prospective and retrospective studies evaluating root resorption after orthodontic intrusion were included. DATA COLLECTION AND ANALYSIS: Risk of bias (RoB) assessment was performed with the Cochrane Collaboration's RoB Tool 2.0 and ROBINS-I tool for the randomized and non-randomized studies, respectively. The data were combined into two random-effects meta-analyses estimating OIRR following orthodontic intrusion. One evaluated OIRR in the anterior region, while the other assessed OIRR in the posterior region. Sub-group analyses regarding the type of mechanics applied, duration of intrusion, amount of force, and sensitivity analysis of the study design and imaging examinations were also performed. The certainty of the evidence was assessed through the Grade of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. RESULTS: The qualitative analysis included 14 studies; however, the meta-analysis was performed with 7 records. The random-effects model assumes that 0.72 mm [95% confidence interval (CI): 0.16 to 1.28] and 0.41 mm (95% CI: -0.24 to 1.07) of OIRR should be expected in the incisors and the molars, respectively. Sub-group analyses showed that the assessed treatment-related factors presented minimum impact in OIRR after orthodontic intrusion. The GRADE resulted in moderate and low certainty regarding the meta-analysis. LIMITATIONS: The major limitation of the present meta-analysis is that OIRR can be affected by several factors, some of which are assessed in this review. CONCLUSIONS: Orthodontic intrusion, evaluated as an isolated mechanic, caused less than 1 mm of OIRR, which is within the acceptable limits for clinical implication. Treatment-related factors did not show a significant influence on OIRR. REGISTRATION: This review was registered in PROSPERO, protocol number CRD42018098495.

Stability of class II treatment with Pendulum and Jones jig followed by fixed appliances.

INTRODUCTION: The present study aimed to evaluate and compare the long-term stability of Class II correction with the Pendulum or Jones jig followed by fixed appliances. SETTINGS AND SAMPLE POPULATION: Group 1 comprised 20 Class II malocclusion patients with a mean initial age of 13.97 years (SD = 1.57), treated with Pendulum and fixed appliances for a mean period of 4.72 years (SD = 0.98), and mean long-term post-treatment evaluation of 4.72 years (SD = 0.97). Group 2 consisted of 18 Class II patients with a mean initial age of 13.19 years (SD = 1.26), treated with Jones jig and fixed appliances for a mean period of 3.96 years (SD = 0.92). Mean long-term post-treatment time was 5.50 years (SD = 1.57). METHODS: Lateral cephalograms were evaluated at three stages: initial (T1), final (T2) and long-term post-treatment (T3). Intragroup comparisons were performed with repeated measures ANOVA and Tukey's test and intergroup comparisons with independent t test. RESULTS: Many treatment changes were observed in both groups. From the long-term post-treatment periods, there was stability for most of the variables. Maxillary second molars and mandibular first molars extruded in the Jones jig group and slightly intruded in the Pendulum appliance group. The nasolabial angle decreased in the Pendulum group and increased in the Jones jig group. CONCLUSION: The correction of a Class II malocclusion was shown to be stable with similar long-term post-treatment results with Pendulum or Jones jig followed by fixed orthodontic appliances.