MBT直丝弓矫治器治疗Ⅱ类2分类拔牙病例上颌切牙变化的研究

目的通过X线投影测量技术，观察分析MBT矫治技术矫治安氏Ⅱ类2分类错耠时上颌切牙转矩及位置变化，为正畸临床实践提供参考。方法选择21例安氏Ⅱ类2分类错耠的病例，采用MBT滑动直丝弓矫治器拔除4个第一双尖牙进行矫治，测量分析矫治前后X线的变化。结果MBT矫治技术能有效控制上颌切牙唇舌向倾斜度，平均增加16．60°；同时切牙的阻抗中心U1R至颚平面的距离U1R-PP平均减少0．53mm。结论MBT滑动直丝弓矫治器对安氏Ⅱ类2分类错耠拔牙病例前牙的转矩有着很好控制，MBT矫治技术是矫治安氏Ⅱ类2分类错耠畸形的有效方法。

Objective To study the effect of controlling the torque of anterior teeth in the class Ⅱ division 2 malocclusion with extraction treated with MBT appliances for improving treatment technique level in clinic. Methods The values of cephalometric analyses before and after the treatment were compared for 21 patients with class Ⅱ division 2 malocclusion who were treated by extraction of four first bicuspids and with MBT technique. Results MBT appliance can effectively control the torque of anterior teeth. After treatment the U1-SN was increases by 16.60° ,and UxR-PP was decreased by 0. 53mm. Conclusion MBT appliance can control the torque of anterior teeth very well when closing the space in the cases of extraction.