Comparative Dentoskeletal Effects of Two Fixed Systems in Treating Class II Malocclusion: A Retrospective Cohort Study

Objectives: Class II malocclusion is a frequent orthodontic problem in growing patients, and understanding the dentoskeletal effects of different treatment approaches is essential for selecting the most appropriate therapeutic strategy. This study aimed to compare the skeletal and dentoalveolar effects of the Carriere Motion appliance (CMA) and the Rapid Maxillary Expander II (RME II) system in growing patients with Class II malocclusion, using an untreated control group. Methods: This study included 86 growing patients with skeletal Class II Division 1 malocclusion, divided into three groups: RME II (n = 28), CMA (n = 28), and untreated controls (n = 30). Lateral cephalograms were obtained at baseline (T0) and after Class II correction (T1). Skeletal and dentoalveolar variables were assessed, and intergroup differences in treatment changes were analyzed using appropriate statistical tests with correction for multiple comparisons. Results: Both treatment groups showed significantly greater reductions in overjet than the control group, with no significant difference between the two appliances. The CMA group showed a greater reduction in overbite, whereas the RME II group showed greater reductions in the A point–Nasion–B point (ANB) angle and greater increases in mandibular length (Condylion–Gnathion; Co-Gn) compared with both the control and CMA groups. Conclusions: Both appliances were effective in correcting Class II malocclusion during growth. However, the CMA was mainly associated with dentoalveolar correction and vertical changes, whereas the RME II system induced more evident skeletal modifications.