因上顎多顆前牙埋伏齒故以犬齒替代上顎正中門齒之案例

Canine Substitution for Upper Central Incisor in A Case of Upper Anterior Teeth Impaction

上顎多顆前牙同時發生阻生和錯位在臨床上並不尋常且對於牙科醫療行為具有相當大的挑戰。前牙埋伏齒若能早期診斷並拔除便可提升其美觀和咬合功能。這個案例報告描述一位18歲女性患者仍存有上顎左右乳犬齒並同時具有兩側犬齒和右側正中門齒皆為彎曲唇側阻生齒。患者兩側乳犬齒、右側正中門齒和左側犬齒被拔除，其右側犬齒則取代成正中門齒、兩側第一小臼齒取代成犬齒。右側犬齒經過手術暴露並使用雙弓線技術引導至正中門齒的位置。經過三十個月的治療，右側犬齒成功取代成正中門齒。治療後咬合功能良好，患者對於微笑曲線的重建相當滿意。此病例報告闡述關於犬齒的替代治療原則、生物力學設計和美觀考量。

The purposes of this literature review were to evaluate and compare the correction rate of posterior crossbite of different kinds of maxillary expansion. The study selection criteria included RCTs involving subjects with posterior crossbite with maxillary expansion which searched from MEDLINE. The search strategy resulted in 10 articles that fitted to the inclusion criteria from 72 searched papers. Five out of ten articles have low bias risk, which are Martina R et al. (2012), Petrén S et al. (2008), Petrén S et al. (2011), Godoy F et al. (2011), McNally MR et al. (2005). The result showed there were no significant difference between RME and SME on treating posterior crossbite. Quad-helix showed better result than removable expansion plate. Posterior crossbites did not be spontaneously corrected during the transition into the permanent dentition.