Subcutaneous emphysema producing airway compromise after anesthesia for reduction of a mandibular fracture. A case report and review of the literature. Subcutaneous emphysema can occur as the result of trauma, surgery, and anesthesia. A case is presented of extensive subcutaneous emphysema after anesthesia for oral surgical reduction of a mandibular fracture. A discussion of the diagnosis, pathophysiology, and treatment of subcutaneous emphysema follows. 