不对称拔牙模式矫治安氏Ⅱ类1分类错的疗效评价

The effectiveness of asymmetric extraction in treatment of Class Ⅱ division 1 malocclusions

目的:分析不对称拔牙模式矫治安氏Ⅱ类1分类错前后软硬组织的变化,为临床治疗方案的选择提供参考。方法:选择安氏Ⅱ类1分类错患者30例(男11例,女19例,平均年龄13.6岁),根据不同的拔牙模式分为2组。实验组拔除2颗上颌第一前磨牙,1颗下颌第一前磨牙;对照组拔除4颗第一前磨牙。对治疗前后头颅侧位定位片进行测量分析,采用SAS6.12软件包进行独立样本t检验,比较2组软硬组织的结构变化。结果:2组矫治前、后组内比较显示,颌骨测量项目NAPog角、SNA角、ANB角、MP-SN角均有显著差异;上、下前牙的倾斜度、突度除实验组的L1-MP角外均有统计学意义;软组织测量项目中,上、下唇倾角,上唇厚度,上、下唇突度,上、下唇长度,Z角和鼻唇角均有显著差异,而下唇厚度、颏沟倾角无显著差异。2组矫治前、后变化量的组间比较显示,仅L1-MP角、U1-L1角的变化量有显著差异。结论:不对称拔牙矫治后,患者的上、下前牙均内收,软组织侧貌明显改善,能达到满意的治疗效果。

PURPOSE： To analyze hard and soft tissue profile changes before and after asymmetric extraction treatment of Angle Class Ⅱ division 1 malocclusion.METHODS： Thirty patients of Angle Class Ⅱ division 1 malocclusions（11 males,19 females,average age 13.6 years） were divided into two groups according to their extraction approach.In asymmetric extraction group,2 first maxillary premolars and 1 first mandibular premolar were extracted.In the control group,all 4 first premolars were extracted.Lateral cephalometric radiographs were taken before and after treatment to compare hard and soft-tissue changes between the two groups,and the cephalometric measurements were analysed by SAS6.12 software package for independent sample t test.RESULTS： In comparison of the changes between the two groups,significant differences in dentoskeletal measurements were observed with NAPog,SNA,ANB,MP-SN and with the inclinations of the upper and lower incisors（P〈0.01）.Significant differences in soft-tissue changes were also observed in the thickness of upper lip,the Z angle（P〈0.01） and the nasolabial angle（P〈0.05）.Compared to the profile before treatment,only inclination of lower incisors changed significantly after treatment（P〈0.01）.CONCLUSIONS： Asymmetric extractions is feasible in treatment of Class Ⅱ division 1 malocclusions evidenced by retractions of both upper and lower incisors and improves sagittal soft-tissue profile.