下颌前导矫形与单纯拔牙矫治对骨性Ⅱ类错畸形的疗效评价

Efficacy evaluation of fixed Twin-block appliance and tooth extraction in skeletal Class Ⅱ malocclusion

目的:通过X线头影测量分析,评价前导矫形联合固定矫治器矫治和单纯拔牙固定矫治对生长发育期安氏Ⅱ类骨性错畸形的临床疗效。方法:选取31例生长发育期安氏Ⅱ类错畸形伴下颌后缩的病例。其中,18例采用Ⅰ期固定式Twin-block矫治器联合Ⅱ期固定矫治;13例采用传统的单纯拔牙后使用直丝弓矫治器进行治疗。在治疗前、Twin-block矫治完成后以及全部固定矫治结束后拍摄X线头颅侧位片,利用Pancherz测量分析法进行分析,使用SPSS15.0软件包分别比较前导矫形组、单纯拔牙组治疗前后的组内差异以及2组的组间差异。结果:前导矫形组下颌骨长度增加并向前移动,上切牙相对于上颌骨的位置向后方移动,下切牙、下颌第一恒磨牙相对于下颌骨的位置均向前方移动,覆盖减小(P<0.05)。单纯拔牙组上、下颌骨的位置、髁突位置及下颌骨的长度治疗前后均无显著变化。在前牙覆盖的纠正中,前导组牙性因素占39.5%,骨性因素占60.5%,拔牙组牙性因素占86.9%,骨性因素占13.1%;在磨牙关系的纠正中,前导组牙性因素占44.9%,骨性因素占55.1%,拔牙组牙性因素占90.3%,骨性因素占9.7%。结论:前导矫形联合固定矫治与单纯拔牙固定矫治相比,在治疗生长发育期骨性Ⅱ类下颌后缩的患者中,疗效近似,但能更显著地改善患者的骨性侧貌。

PURPOSE： To evaluate the skeletal and dentoalveolar effects of Twin-Block combined with straight wire appliances and tooth extraction in the treatment of skeletal Class Ⅱ malocclusion with mandibular retrognathia in growing individuals. METHODS： The sample comprised 31 growing individuals with skeletal Class Ⅱ and mandibular retrognathia, divided into 2 groups. One group （18 patients） was treated with fixed Twin-block combined with fixed appliance; the other group （13 patients） was only treated with fixed appliance after tooth extraction. Lateral cephalograms pretreatment and posttreatment were taken before and after Twin-block treatment and after all fixed appliance treatment. Pancherz＇s cephalometrie measurements were analyzed statistically. Intragroup and intergroup changes of the two groups were evaluated by test using SPSS 15.0 software package. RESULTS： According to Pancherz＇s analysis, mandibular length increased, point Pg, mandibular incisors and first molars moved forward, maxillary incisors moved backward, overjet decreased （P〈0.05） after treatment with Twin-block and fixed appliance. Within the rectification of anterior overjet, proportion of dentofacial factor was 39.5%, skeletal factor was 60.5%. Within the rectification of posterior relationship, proportion of dentofacial factor was 44.9%, skeletal factor was 55.1%. CONCLUSIONS： Twin-block combined with fixed appliance treatment can efficiently promotemandibular growth, restrict forward growth of maxilla to some extent, correct incisor and molar relationship and improve skeletal profile in growing skeletal Class Ⅱ individuals with mandibular retrognathia.