皮下氣腫和縱膈腔氣腫是指空氣聚積在正常情形下不會出現的位置，如皮下組織，深層結締組織，甚至於縱膈腔。醫源性的原因通常是發生在外科手術之後，發生在一般牙科處置甚至是牙齒拔除之後卻是相當地罕見。本文我們提供了一個拔除第三顆大臼齒之後造成皮下氣腫和縱膈腔氣腫的臨床個案報告。根據我們回顧的文獻發現，造成原因多半與牙科醫師常會使用的高速氣渦式手機有很大的相關。本篇文章的目的是希望提醒臨床醫師，牙科術後造成的縱膈腔氣腫雖然少見，但是由於併發症可能會危及生命，且易與其他疾病混淆，導致延誤治療，因此針對相關機轉、診斷及處置進行探討，並期能幫助臨床醫師及早診斷。

Subcutaneous emphysema and pneumomediastinum imply free air within the subcutaneous and the mediastinum. They are well-known associated to trauma and surgery procedure, but relatively rare secondary to dental extraction. A case is described of acute subcutaneous emphysema and pneumomedisatinum after third molar extraction with using a high-speed dental handpiece. We review the literature and discuss the possible mechanism. Although they are rare but serious and easily misdiagnosed in the primary clinics and emergency department, physicians should be more aware of these.