Sudden Onset of Subcutaneous Air Emphysema After the Application of Air to a Maxillary Premolar Located in a Nonsurgical Field.

Although rare, subcutaneous air emphysema can occur during dental procedures such as endodontic treatment, surgical extractions, and preparing a tooth for an indirect or direct dental restoration. We report the development of a subcutaneous air emphysema that was introduced through the periodontal ligament of an untreated premolar after the use of an air syringe to dry the tooth.