嚴重下顎前突症之正顎手術治療－病例報告

Orthognathic Surgery for Severe Mandibular Prognathism-Case Report

童元釔(Yuan-Yi Tung) ； 楊雅慧(Ya-Hui Yang) ； 郭生興(Sang-Heng Kok) ； 張心涪(Hsin-Fu Frank Chang) ； 賴向華(Eddie Hsiang-Hua Lai) ； 姚宗珍(Chung-Chen Jane Yao) ； 陳羿貞(Yi-Jane Chen)

《中華牙醫學雜誌（中文版）》 25卷4期 (2006/12) Pp. 271-280

https://doi.org/10.7106/CJD.200612.0271

摘要

前牙錯咬合併下顎骨骼前突或下顎骨偏移的第三類咬合異常，在一般成人矯正病例中是較具挑戰性的問題，正確的診斷及周詳的治療計劃是矯正治療成功的要件，必要時配合正顎手術的運用，才能使病人得到完善的治療。本報告病例是一位22歲女性病患，主訴為下顎過長以及上顎前牙突出影響顏面美觀。經過資料的收集與分析後，診斷病人為骨骼性第三類咬合異常伴隨下顎骨前突及向左偏移，治療計劃包括：(1)拔除上顎雙側第一小臼齒改正上顎門牙前突，藉著去除齒性代償增加前牙錯咬。(2)利用正顎手術來改正下顎過長及下巴向左歪斜的問題。在這個病例治療過程中，矯正治療與正顎手術術式略有調整，將下顎雙側第一小臼齒拔除後進行前齒槽區後縮手術合併下顎後退10mm及下頦整形術後退5mm，手術後穩定性相當良好，顏面美觀與咬合關係也獲得大幅改善。本病例的治療過程與結果分析顯示對於需接受正顎手術治療的第三類異常咬合病例，進行手術前“去代償”的齒軸角度調整時，應該仔細觀察前牙水平覆咬的變化來判斷與預測目標的差距，並且藉由術前所拍攝的測顱X光片分析前牙齒軸變化，以做為後續調整的依據。

關鍵字

骨性第三級咬合異常 ； 正顎手術下顎枝截骨術 ； 前齒槽後縮 ； 下頦整形術

並列摘要

It is a challenge in adult patients to correct a class Ⅲ malocclusion and anterior crossbite combined with mandibular prognathism or deviation. A proper diagnosis and careful treatment planning are the key to success. If the degree of skeletal class Ⅲ discrepancy, anterior crossbite, or chin deviation cannot be corrected through conventional orthodontic methods, orthognathic surgery can be very effective. This case report describes a 22-year-old female, who complained of poor esthetics because of the long length of her mandible and a protrusive maxilla. After a routine orthodontic examination, the diagnosis was skeletal class Ⅲ malocclusion with mandibular prognathism and a side shift. The treatment plan consisted of extraction of the upper bilateral first premolars to correct the maxillary protrusion, and dental decompensation to display the actual skeletal discrepancy. In this way, a mandibular setback and side shift could be performed to improve the protrusive mandible and chin deviation problems. After about a 1-year treatment duration, we reevaluated the pre-surgical preparation for the orthognathic surgery. We found that the amount of dental decompensation was greatly in excess of the predicted amount. So we shifted our surgical plan to 2-jaw surgery: maxilla advancement combined with mandibular setback. But for financial and surgical-risk considerations, the patient declined this option. Therefore, we decided to extract the lower bilateral first premolars, and produce mandibular setback combined with an anterior subapical osteotomy. After the decision, we allowed 6 months for the pre-surgical preparations, while postsurgical detailing consumed another 6 months. After treatment, the patient was very satisfied with the treatment outcome, and became more confident. This was a case of changing treatment plans. We analyze the difference in dental decompensation between the predicted and actual outcomes; we also discuss details of the orthognathic surgery.

並列關鍵字

skeletal class Ⅲ malocclusion ； sagittal split osteotomy ； anterior subapical osteotomy ； genioplasty