Abstract:

Objectives

The purpose of this study is to evaluate the effect of treatment Angle class Ⅱdivision Ⅰwith mandibular retraction in young adults with Twin-block appliance and fixed appliance.

Methods

11 cases of Angle class ⅡdivisionⅠwith 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 ⅡdivisionⅠmalocclusion with mandibular retraction in young adults. It is suggested that this treatment method could be an alternative to orthognathic surgery in borderline Class Ⅱcases.

Key words: Angle Class Ⅱ Maloclusion, mandibular retrusion, Twin-block appliance