Coronectomy is an alternative to traditional mandibular third molar extraction when the inferior alveolar nerve (IAN) is closely associated with the roots of these molars. Given the paucity of research on the long-term outcomes after coronectomy, we conducted this study to evaluate clinical and radiographic outcomes at least 5 years post-coronectomy.

This retrospective study enrolled all patients with impacted mandibular third molars treated with coronectomy at our institution who were willing to return for follow-up evaluation 5 years or more after their original procedure. Patient data were obtained retrospectively from hospital records and during oral examinations at the follow-up study appointment. We assessed the following postoperative clinical outcomes: injury to the IAN, root migration distance, root exposure in the oral cavity, non-healing sockets, pain or sensitivity in the coronectomy area, and the presence of periapical pathology.

Of the 196 patients invited to participate, 66 patients (male, 32 %; female, 68 %) who underwent a total of 75 coronectomies were included in this study. No persistent hypoesthesia of the lower lip were reported during follow-up. Two patients required reoperation because of root eruption into the oral cavity. Approximately two-thirds of residual roots migrated from their position on preoperative radiographs; the mean migration distance was 3.2 ± 1.3 mm. Two patients (2.6 %) had pain in the soft tissues around the coronectomy site.

Our findings confirm that coronectomy is an effective treatment option for preventing IAN injury when the nerve is in close proximity to the roots of these molars.