三級關係咬合不正的治療時機與策略－－文獻回顧

The Proper Timing and Strategies to Initiate Orthodontic Treatment for Patients with Class III Malocclusion – A Literature Review

對於三級關係咬合不正的治療時機，因為難以準確預估其生長模式，一直以來是備受爭議的主題。回顧文獻可發現許多早期治療的方式試圖達到骨矯正的效果以降低之後治療的複雜性或手術的需求，也討論在不同齒齡與生長潛力時開始治療是否會有不同的結果。而系統性的回顧文獻也指出骨頭的改變量與年紀有關，但若是在青春期以前開始的治療，最後的成果並不會因為混合齒列的分期造成顯著差異。在正確的診斷後所做的骨矯正治療中，以面弓拉出的方式在短期可達75%的成功率，但仍存在很大的個體差異，也仍無法準確預估治療效果。另一方面，以頭帽（chincap）抑制下顎的生長已有長期追蹤的研究顯示無法維持抑制長度的成果，只能改變部分的生長方向。本篇文獻目的為整理三級關係咬合不正的治療方式與介入時機，如何選擇是否早期治療，以及治療的效果和穩定性。

Treatment for Class III malocclusion has been a controversial issue due to the unpredictable growth pattern. According to the literatures, various early interventions have been proposed to modify the skeletal relationship in order to reduce the need for the future complex orthognathic surgery. The influences of the age and the growth potential of patients at the time of treatment were also commonly discussed. Systematic review of the literatures showed that the amount of orthopedic effect was related to the age of patients; however, for those that start treatment before puberty, the stage of the mixed dentition at time of treatment was not relevant to the final result. With proper diagnosis, protraction with facemask resulted in 75% short-term success rates. Yet individual variations did exist, and predictable results were still unavailable currently. On the other hand, studies of chincap treatment with long-term follow up indicated that chincap could only partly alter the direction of mandibular growth but not suppress the mandibular growth per se. The aims of this review are to discuss the treatment methods of Class III malocclusion, the time frame of treatment intervention, and the decision making on early treatment, as well as the treatment effect and stability.