年轻成人安氏I类错亚型的X线头影测量分析

Cephalometric analysis of the subdivision characteristic of Angle's ClassⅠmalocclusion in the young adults

目的:分析年轻成人安氏Ⅰ类错亚型特征。方法:选取101例安氏Ⅰ类错年轻成年患者,拍摄颅颌定位X线片。用头影测量"优选法"的17项测量指标,按水平方向和垂直方向进行聚类分析,并与正常人群进行比较。结果:测量指标按水平方向可聚类为3个亚类,即水平Ⅰ类、Ⅱ类和Ⅲ类,所占比例分别为17.8%、12.9%和65.3%。水平Ⅰ类特征:上颌略偏缩、下颌后缩,Ⅱ类错趋势,上下中切牙唇倾;水平Ⅱ类特征:上颌前凸、下颌后缩,上下中切牙舌倾,上下唇相对于上下切牙突度大;水平Ⅲ类特征:上颌前凸、下颌后缩,上下中切牙唇倾,上下唇相对于上下切牙突度大。按垂直方向聚为Ⅰ类,特征是垂直方向发育不足,尤其是面下1/3为著,下颌呈后旋趋势,上下唇突。结论:年轻成人安氏I类错水平方向分为3个亚类、垂直方向为Ⅰ类。总体趋势是下颌后缩、面下1/3发育不足,但上颌骨、上下前牙和唇位等方面仍有一定的差异,临床应针对性诊治。

Objective To analyse the subdivision characteristic of Angle＇s Class I malocclusion in the young adults. Methods 101 samples with Angle＇s Class I malocclusion were selected from university students. X ray cephalometric films were photographed and analysed by ＂well-selected method＂ from the measurement software of stomatological hospital,the Fourth Military Medical University.And the seventeen quotas measurement results were accumulated into subdivisions at horizontal and vertical directions and compared with that of the normal occlusion. Results They were accumulated into 3 subdivisions at horizontal direction and 1 subdivision at vertical direction. The percentage of horizontal I , II and III was 17.8%,12.9% and 65.3% accordingly.Compared with the normal occlusion people,horizontal I subdivision showed slightly maxilla retrusion,mandible retrusion,Class II malocclusion tendency and more labial inclined upper and lower central incisors.Horizontal II subdivision showed maxilla protrusion,mandible retrusion,more lingual inclined upper and lower central incisors and more protruded lips.Horizontal III subdivision showed maxilla protrusion,mandible retrusion,more labial inclined upper and lower central incisors and more protruded lips.Vertical I subdivision indicated ill-developed facial lower third,a little more backward rotation and more protruded lips. Conclusion Horizontal 3 subdivisions and vertical 1 subdivision were included in the young adults with Angle＇s Class I malocclusion.The total tendency was mandible retrusion and ill-developed facial lower third,but different maxilla,central incisors and lip protrusion.