先使用快速上顎擴張器結合頦托，再以固定式的矯正裝置及面罩改正前牙錯咬－－病例報告

Using Rapid Maxillary Expander Plus Chin Cap to Correct Complete Anterior Cross Bite Followed by Fixed Appliance with Facial Mask–A Case Report

前牙錯咬的病例並不少見，是安格氏第三級異常咬合的特色之一，在中國人的好發率是4至14%。快速上顎擴張器已被成功使用在改正上顎的橫向、直向、矢向狹窄的問題，且同時有擴大鼻腔空間的作用，進而改善鼻塞的效果。本文提出一位十歲四個月的女性，主訴前牙錯咬，有過敏及鼻塞的病史。經診斷為安格氏第三級異常咬合合併前牙錯咬、中臉凹陷及齒列空間不足。快速上顎擴張器的使用方法為每天轉兩次，加上24小時配戴chin cap，經廿一天後，垂直覆咬及水平覆咬恢復正常，犬齒萌發空間也變得足夠，接著三個月的固定期間chin cap改為晚上戴，最後利用固定裝置完成排列。本文目的是說明如何利用快速上顎擴張器加上chin cap之早期治療，改正前牙錯咬的案例。治療結果顯示，經由早期診斷及利用快速上顎擴張器加上chin cap治療，能有效改善外觀及咬合關係，同時鼻塞的現象也有改善。

Anterior cross bite is not rare and is one of the characteristics of class III malocclusion. The prevalence rate is about 4-14% in Chinese children. Rapid Maxillary Expander ( RME ) has been successfully used for many years because it is not only used for correction of vertical, transverse and sagittal dimension of maxilla but also exert on reduction in nasal airway resistance. A 10 years 4 months old Chinese girl came with a chief complaint of anterior cross-bite and severe crowding. She had allergy history with nasal congestion. Complete anterior crossbite and mid-face deficiency with severe dento-alveolar discrepancy on upper arch with canine impaction was diagnosed. There was a presence of functional shift, good CR profile, class I canine and molar relationship, deeper overbite. Rapid maxillary expansion plus chin cap was used in 21 days and 3 months retention with good compliance. Then fixed appliance with facial mask was applied for teeth alignment. The aim of this report is to correct anterior crossbite in an early age and show how to use RME plus chin cap. Our results suggest that early treatment of pseudo-class III by using RME plus chin cap followed with fixed appliance and facial mask is effective in improvement of anterior crossbite and profile.