Short and long-term skeletal and dental effects of the mandibular anterior repositioning appliance in Class II malocclusion: a systematic review and meta-analysis

Abstract

Objectives. This systematic review assessed the skeletal and dental effects produced by the Mandibular Anterior Repositioning Appliance (MARA) in growing patients with Class II malocclusion and mandibular retrusion, examining both immediate and long-term treatment outcomes. Material and methods. A comprehensive electronic search across nine databases, along with manual searching, was conducted through July 1, 2025, yielding 1,073 records. After duplicate removal and screening, 29 full-text articles were assessed for eligibility; 12 studies were included in the qualitative synthesis, comprising 7 retrospective cohort studies and 5 prospective controlled clinical studies, and 11 were eligible for meta-analysis. Data were extracted according to the timing of outcome assessment. Risk of bias was assessed, and the certainty of the evidence was evaluated. Random-effects meta-analyses were performed with 95% confidence intervals. Results. Twelve observational studies including growing patients with Class II malocclusion were included. MARA produced limited skeletal effects but significant dentoalveolar effects. In the short term, IMPA increased by 4.16°, and the interincisal angle decreased by 8.67°. Long-term follow-up showed further increases in IMPA (5.04°) and a continued reduction in the interincisal angle (6.34°). Significant improvements in overjet and overbite were observed, primarily through dentoalveolar adaptation rather than skeletal correction. Conclusion. Based on evidence derived entirely from observational studies, which was assessed by GRADE as very low certainty, MARA produced predominantly dentoalveolar rather than skeletal effects. Statistically significant reductions in overjet and overbite, together with increased lower incisor proclination, were the most consistent findings; however, their clinical significance remains uncertain due to substantial heterogeneity. No significant change in mandibular position was detected, suggesting limited true skeletal correction. These findings should be interpreted with caution, and definitive clinical recommendations require higher-certainty evidence from future randomized controlled trials.