Combined Endodontic and Surgical Treatment of Dens Invaginatus-Associated Extraoral Fistula: A Case Report with Seven-year Follow-up.

Dens invaginatus (dens in dente) is a developmental malformation of permanent or deciduous teeth that has various complex forms. It most commonly affects permanent maxillary lateral incisor teeth, and rarely affects the mandibular teeth. In this report, a rare case of dens invaginatus of a mandibular lateral tooth with an extraoral fistula is presented. A 10-year-old patient was referred to our clinic with extraoral symptoms that could not be diagnosed by medical doctors. Successful treatment with endodontic treatment and periapical surgery is described. Seven-year follow-up of the case is provided.