骨面型Ⅲ类错正畸治疗前后颏部软组织侧貌形态变化

Changes in morphological characteristics of chin soft tissue profile before and after class Ⅲ malocclusion treatment

背景:以往有关探讨颏部形态变化的研究主要是对正畸治疗前后牙齿、颌面部软硬组织进行测量分析。目的:观察青少年安氏Ⅲ类错治疗前后颏部软组织侧貌的形态结构特征。方法:选取符合骨面型Ⅲ类,ANB<0°,同时符合安氏Ⅲ类,轻中度骨性畸形48例青少年,对矫治前、后X射线头颅侧位定位片进行测量,比较分析治疗前后颏部软组织形态结构变化。结果与结论:骨性Ⅲ类治疗后患者颏唇沟深度增加(P<0.01),颏部长度、颏唇沟弧度、颏部弧度较治疗前均有所减小(P<0.01),而反映颏部突度的各项测量值如下唇突点、颏部软组织之凹点、软组织颏下点到E线的垂直距离均比治疗前有所减小(P<0.01或P<0.05)。证实安氏Ⅲ类错在正畸治疗后较治疗前颏部形态有所改善。

BACKGROUND：Previous studies regarding morphological characteristic of mental region are performed to quantitatively analyze the soft and hard tissue of tooth and mental region before and after treatment.OBJECTIVE：To investigate the changes in morphological characteristic of chin soft tissue profile before and after class Ⅲmalocclusion treatment.METHODS：The sample was composed of 48 adolescents aged 12-16 years who presented class Ⅲ malocclusion.Cephalograms were analyzed for all subjects,and the morphology of the symphysis before and after treatment was measured.Paired student＇s t test was performed through the use of SPSS16.0 software package.RESULTS AND CONCLUSION：After treatment,the length of chin（LL-Pos） decreased（P=0.000） ,Bs-LLPos was larger（P=0.000） ,∠LL-Bs-Pos（P=0.000） and ∠Bs-Pos-Mes（P=0.004） were decreased compared with before treatment.After treatment,all cephalogram dates of chin convexity were smaller compared with before treatment（P〈0.05） .The thickness of chin soft tissue was decreased after treatment compared with that before treatment（P〈0.05） .The morphological characteristic of chin soft tissue became better after treatment compared with before treatment.