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Abstract

Objective: This study aims to evaluate the effectiveness of the Shorty Carriere Motion Appliance (CMA), bonded from the maxillary first premolar to first molar, in treating Class II malocclusions and to compare its treatment outcomes—including maxillary dental movements, anteroposterior correction, bite opening, and treatment duration—with those achieved using the Standard CMA, bonded from the maxillary canine to first molar. Methods: This retrospective cohort study assessed the outcomes of the Shorty and Standard CMA protocols in patients with Class II malocclusions undergoing comprehensive orthodontic treatment at two private practices in Vancouver, Canada, and at the University of British Columbia (UBC). A total of 48 adolescent and adult patients (ages 10–35) with Class II dental malocclusions and complete orthodontic records were included. Eighteen patients received the Carriere appliance bonded from the maxillary first premolar to the maxillary first molar (Shorty), while 30 patients received the appliance bonded from the maxillary canine to the maxillary first molar (Standard). Digital dental models were analyzed at two time points: T0 (initial) and T1 (post-CMA treatment). Superimpositions of T0 and T1 models were used to assess tooth movement across all three spatial planes. Data on occlusal plane changes and appointment characteristics were also collected. Results: Superimposition analysis revealed some statistically significant, but clinically insignificant differences between the Shorty and Standard groups in terms of maxillary tooth distalization, extrusion, buccal movement, rotation, occlusal plane rotation, or treatment duration. In addition, several notable side effects were encountered in some patients, including posterior crossbites and open bites. Conclusions: Both the Shorty and Standard CMA protocols produce comparable outcomes in the treatment of Class II malocclusions with regards to maxillary dental movements.