運用上顎快速擴張器（RME）與頤帽（Chin Cap）裝置治療生長發育期之前牙錯咬病患

Orthodontic Treatment for a Class III Malocclusion Growing Patient by Using RME and Chin-cup Appliance–Case Report

第三類咬合異常病患的治療一直是令矯正醫師們很頭痛的問題，特別是在生長發育期的患者。而這類生長期的兒童，常合併有中顏面發育不足及前牙錯咬的問題，本文提出一位八歲十一個月女性，主訴前牙錯咬，經診斷為安格氏第三類異常咬合合併前牙錯咬，中臉部凹陷及下唇前突，使用上顎快速擴張器（RME）配合頤帽（Chin cap）裝置的治療法，上顎快速擴張器的使用方法為每天兩轉（0.5 mm）配合每日至少21小時配戴chin cap，經過四周治療，上顎骨因RME往前推，同時下顎骨向後下方旋轉，藉此改善前牙錯咬及戽斗臉型的問題。

The early treatment of skeletal Class III malocclusion is one of the most challenging problems that orthodontists may encounter. These patients often combine maxillary deficiency with anterior crossbite. In this report, an 8-year-old female patient with Class III malocclusion, anterior crossbite and protrusive lower lip. (SNA: 83.5°, SNB: 83°, ANB: 0.5°, overjet: -1.5mm, overbite: +2.5mm, mandibular plane to SN: 26.7°), received orthodontic treatment with rapid maxillary expansion and chin cup appliance. We used RME 2 turns (0.5mm) per day, and wore the chin cup at least 21 hours per day, to force mouth closure and enhance nasal breathing. Active orthodontic treatment time was 4 weeks. The retention period of RME was 3 months. The treatment results showed that maxilla was pushed forward by RME. and mandibular clockwise rotation, which improve anterior crossbite and facial profile. The treatment outcome were stable after 3 years follow up.