埃勃斯坦畸形（Ebstein anomaly）亦稱為三尖瓣下移畸形，是三尖瓣位置過低而造成心房化心室現象，使得部份的右心室變成右心房，因此右心室變得非常的小。埃勃斯坦畸形是一種少見（＜1％）的先天性心臟病。臨床症狀的嚴重度依三尖瓣的移位程度而有所不同。大部分的症狀只有疲倦，但也可能出現運動喘氣現象、發紺或心臟衰竭的情形。本篇報告在介紹一位患有Ebstein anomaly的三歲四個月大男童，在經過診斷及評估後於門診完成全口治療。臨床上遇到患有埃勃斯坦畸形（Ebstein anomaly）幼童或其他先天性心臟病的小病人，在進行牙科治療時應該要注意的臨床表徵及預防給藥，以及可能發生的合併症將於此病例報告中一併討論。

Ebstein anomaly is a congenital malformation of the heart that is characterized by apical displacement of the septal and posterior tricuspid valve leaflets, leading to atrialization of the right ventricle with a variable degree of malformation and displacement of the anterior leaflet. Ebstein anomaly occurs in less than 1% of all congenital heart defects. Signs & symptoms include fatigue, shortness of breath during play,palpitation, cyanosis or congestive heart failure. This case report presented a 3-year-4-month old boy with Ebstein anomaly and multiple severe dental caries successfully received full mouth dental treatment at chair side. Dental considerations of Ebstein anomaly were also discussed in this case report.