Clincical research on treatment of Angle class II divisionIyoung adults with mandibular retraction by Twin-block appliance

Objectives The purpose of this study is to evaluate the effect of treatment Angle class Ⅱ division Ⅰ with mandibular retraction in young adults with Twin-block appliance and fixed appliance. Methods 11 cases of Angle class Ⅱ divisionⅠwith mandibular retraction were included. All subjects were treated with Twin-block appliance and fixed appliance without extraction. Cephalograms were taken before and after treatment. Cephalometric analysis was conducted to evaluate the treatment effects. Student's t test was used to determine the effect on jaw changes, teeth movement and profile changes before and after treatment. Results After treament, ClassⅠmolar relationship was achieved in all subjects. Skeletal and soft tissue facial profile convexity were reduced. Conclusion Twin-block appliance is effective in the treatment of Angle class Ⅱ divisionⅠ malocclusion with mandibular retraction in young adults. It is suggested that this treatment method could be an alternative to orthognathic surgery in borderline Class Ⅱ cases.