Subcutaneous facial emphysema complicating dental anaesthesia.

A 20 year-old female developed swelling and protrusions of the tongue and marked facial swelling while under general anaesthesia for dental restoration and gigivectomy. The initial diagnosis was angioedema; however x-rays showed marked subcutaneous emphysema more extensive in the perimandibular area with a minimal amount in the neck. There was no evidence of pneumomediastinum or pneumothorax. The iatrogenic subcutaneous emphysema was felt to be due to air-driven dental equipment. Tracheal intubation was maintained for 21 hours to prevent airway obstruction. The patient was treated with oxygen and antibiotics. Subcutaneous emphysema may occur following root canal therapy, tooth extraction, periodontal surgery and operative dentistry, due to the use of air-driven dental equipment. It has the potential to cause obstruction.