Abstract: Objective: To compare the effectiveness and efficiency of orthodontic appliances used in correcting anterior crossbite with functional mandibular shift in the mixed dentition. Methods: Forty-seven patients treated in our department were selected. The inclusion criteria was: mixed dentition, anterior crossbite with functional mandibular shift, mild space deficiency in the maxilla, a non-extraction treatment plan, retracted to an edge-to-edge incisor relationship, no history of systemic disease, and written consent obtained. The patients were treated either with a removable appliance with protruding springs combined with/without facemask protraction or a fixed appliance with multi-brackets combined with removable mandibular appliance or a FRIII combined with myofunctional training. The main outcome measures assessed were success rate, duration of treatment, times of visit, and costs of treatment. Results: The anterior crossbite was successfully corrected in all patients except one self-terminated case. The average duration and cost of patients treated with removable appliance without facemask were significantly lower (P<0.05). The alignment of four maxillary incisors in the fixed appliance group was more aesthetic, however, extraordinary retention was needed. Conclusion: Anterior crossbite with functional mandibular shift in the mixed dentition can be successfully corrected by either removable or fixed or FRIII appliance therapy in a short-term perspective.

Key words: Mixed dentition, Anterior crossbite, Orthodontic treatment, Functional shift