Twin-block appliance in treatment of Angle class II division 1 malocclusion

Objective To observe the clinical effect of Twin-block appliance on Angle Class II division 1 malocclusion.Methods Seventeen children with Angle Class II division 1 malocclusion and mainly with mandibular retrognathia were selected.Twin-block and MBT appliances were used to correct in the first and second phases,respectively.Clinical effect was evaluated by cephalometric analysis before and after treatment.Results There were obvious mandible changes such as the increase of SNB angle and decrease of ANB angle and overjet after treatment with Twin-block,suggestive of mandible growth,increase of facial angle,reduction of mandible process angle,mild adduction of upper incisors,and mild anteversion of lower incisors.Conclusion Twin-block appliance possesses the orthopedic effect on Angle class II division 1 malocclusion.