Subcutaneous emphysema in patients undergoing root canal treatment: a systematic review of the factors affecting its development and management.

Subcutaneous emphysema can develop during both nonsurgical and surgical root canal treatment. Pressurized air streams or air-water sprays should not be directed towards the root canals or areas with mucosal discontinuity. None of the management approaches were clearly related to expedited recovery. Guidelines should be developed in order to avoid unnecessary or potentially harmful interventions.