Influence of fixed appliances on two-phase orthopedic-orthodontic treatment

Aim: The purpose of this retrospective study was to investigate the effects of phase 2 with fixed appliances, after phase 1 Bionator treatment of Class II division 1 malocclusion, as compared to a matching control group. Methods: The experimental group consisted of 20 patients who were evaluated after orthodontic treatment with fixed appliances subsequently to functional therapy with the Bionator in phase 1. A control group consisting of 20 Class II, division 1 individuals. Results: During phase 1 there was significant forward growth restriction in the maxillary complex, improvement of the maxillomandibular relationship and decrease in facial convexity. There was also significant reduction of the maxillary incisor proclination and protrusion, protrusion of the mandibular incisors, and vertical development of the mandibular molars. The overjet was significantly reduced and the molar relationship was significantly improved. Treatment during phase 2, with fixed appliances, resulted in significant maxillary forward growth restriction and facial convexity reduction. Conclusion: Major Class II skeletal and dentoalveolar anteroposterior correction was obtained during phase 1, with the Bionator. Phase 2, with fixed appliances only produced a significant maxillary forward growth restriction and facial convexity reduction, without any significant dentoalveolar change