中文摘要：

目的探讨经正畸正颌联合治疗的骨性Ⅲ类错（牙合）畸形患者的术前术后正畸治疗特点。方法 25例经完善的正畸正颌联合治疗的骨性Ⅲ类错（牙合）畸形患者,分析治疗前（T0）、术前正畸治疗后（T1）、及矫治结束后（T2）的头颅定位侧位X线片,分析其不同时期的硬组织变化,总结术前术后正畸治疗特点。结果所有患者面部外形都较治疗前明显改观,咬合及功能改善。尽管头影测量结果显示骨面型：面角、颌凸角等变化明显,但术前正畸去代偿并不完全,上颌牙齿的代偿依然存在。术后的正畸主要是稳定手术后的颌骨关系和精细调整咬合,类似于综合性的正畸治疗。结论正畸正颌联合是治疗骨性Ⅲ类错（牙合）畸形的有效手段,而治疗效果的日臻完善需要正畸正颌治疗的密切配合。

英文摘要：

Objective To analyze features of presurgical and postsurgical orthodontic treatment of patients with skeletal class Ⅲ malocclusion in orthodontic-orthognathic surgical treatment.Methods The study included 25 skeletal class Ⅲ patients treated with orthodontic-orthognathic surgical treatment.Lateral cephalograms were taken before treatment（T0）,after presurgical orthodontic treatment（T1） and after correction（T2） for each patient.Analyze changes in hard tissue at different stages and summarize features of orthodontic treatment before and after surgery.Results Improvement of profile and functional occlusion of patients was obtained.The facial angles,and angles of convexity had an obvious change after treatment,however,dental decompensation of orthodontic treatment before surgery was not complete.Compensation of maxillary teeth still existed.Orthodontic treatment after surgery was mainly for fixation of jaw relationship after surgery and for delicately adjustment of occlusion,which was similar to comprehensive orthodontic treatment.Conclusions Orthodontic-orthognathic surgerical treatment is effective in treating skeletal class Ⅲ patients.Close cordination between orthodontic treatment and orthognathic surgery is required to improve the treatment effects.