下颌前伸矫治器-3治疗安氏Ⅱ类错后软组织侧貌变化的研究

目的探讨生长发育期安氏Ⅱ类错患者用下颌前伸矫治器-3(MPA-3)矫治后,软组织侧貌的变化。方法选择12例安氏Ⅱ类1分类错患者,下颌后缩,ANB>5°。使用MPA-36～9个月后(平均7.2个月),测量治疗前后X线头颅定位侧位片,进行统计学分析。结果使用MPA-3后,表示软组织侧面突度的面凸角增加了3.57°,软组织面角增加了1.32°,软组织鼻颏角减小了2.40°,Z角增加了6.53°,下颌凸距增加了1.42mm;体现上下唇关系的上唇角减小了4.67°,上下唇角增加了13.16°,上下唇基角减小了2.61°,下唇基角增加了3.32°,颏厚度增加了2.22mm。结论MPA-3是一种有效的固定式功能性矫治器,可以刺激下颌骨的生长,抑制上颌骨的生长,改善骨性矢状关系的不调,同时还可以协调鼻、唇、颏之间的关系,改善面部软组织侧貌和上下唇关系。

Clinical effects on treatment of patients with classⅡmalocclusion by mandibular protraction appliance

Objective To evaluate the effects of soft tissue profile changes of Angle's class Ⅱpatients during growth and development period treated by mandibular protraction appliance-3(MPA-3) with cephalometric analyses.Methods 12 patients with class II,division 1 malocclusion(aged from 11 to 15,average 13;6 males and 6 females) were treated by MPA-3(period ranging from 6 to 9 months,average 7.2 months).The cephalometric analyses before and after treatment were analyzed by paired samples t test.Results After using MPA-3,the parameters representing degree of facial protrusion increased,the angle of convexity increased by 3.57°,soft tissue facial angle increased by 1.32°,and Z angle increased by 6.53°;the parameters representing the relationship of upper and lower lip changed as follows:angle of upper lip decreased by 4.67°,angle of upper and lower lip increased by 13.16°,cardinal angle of upper and lower lip decreased by 2.61°,cardinal angle of lower lip increased by 3.32°,and thickness of chin increased by 0.22mm.Conclusion MPA-3 was an effective fixed functional appliance.It could not only stimulate the mandible development and inhibit the maxillary development to improve osteo-anteroposterior axes relationship,but also coordinate the relationship of nose,lip and chin,improve profile of facial soft tissue and relationship of upper and lower lip to make the Angle's classⅡ patients with retrusive mandible seem more natural and beautiful.