目的　分析替牙期前方牽引器矯治安氏Ⅲ類錯前牙反中骨性和牙性變化。方法　選擇2 0例安氏Ⅲ類錯前牙反患者 ,在替牙早期使用前方牽引器 ,治療開始、治療結束及治療結束后一年拍攝頭頗側位片 ,并以Pancherz分析法進行頭影測量分析。結果　表明 ,在治療剛剛結束時 ,覆蓋增加 6 5毫米 ,其中 40 %為骨性變化 ,6 0 %為牙性代償。治療結束后一年發現覆蓋減少 1 2毫米 ,即骨性變化占 2 3% ,牙性代償 77%。覆蓋減少的原因為下頜向前生長和下切牙唇傾. Objective To show the skeletal and dental changes contributing to the correction of Class Ⅲmalocclusion with reverse headgear in the mixed dentition.Method Twenty patients with anterior crossbite were treated with reverse headgear in the early mixed dentition.Lateral cephalometricfilms taken at the beginning,the end of the treatment and one year after the active treatment,were analyzed with Pancherz analysis.Results and Conclusions After active treatment,the overjet correction was 6.5mm using reverse headgear.40% of the overjet correction was due to skeletal changes and 60% due to dental changes.During the twelve months follow-up period the overjet was decreased by 1.2mm and skeletal changes contributed to 23% of overjet correction.This decrease was mainly due to forward growth of the mandible and proclination of lower incisors.