Odontogenic sinus tracts.

Odontogenic sinus tracts are the most common cause of a chronically draining, fixed, nodulocystic papule of the face and neck. Injury or disease of a tooth may result in a periapical abscess that subsequently dissects along the path of least resistance and erupts through the skin. If recognized early, the sinus tract usually resolves after appropriate endodontic therapy or extraction.