Injury to the inferior alveolar and lingual nerves in successful and failed coronectomies: systematic review

The aim of this systematic review was to evaluate the incidence of damage to the inferior alveolar (IAN) and dental nerves in successful coronectomies, and to compare the results with coronectomies that failed. To the best of our knowledge no such analyses have been reported. Between January 1990 and October 2016 we surveyed published papers to find those that examined clinical outcomes after coronectomy. Fourteen met the criteria for final inclusion. Of 2087 coronectomies, 152 failed (7%). Successful procedures were associated with a low overall incidence of injury to the IAN (0.5%) and lingual nerve (0.05%). The incidence of injury to the IAN in failed coronectomies was 2.6%. The incidence of permanent paraesthesia was 0.05% in successful coronectomies and 1.3% in those that failed. No permanent injury to the lingual nerve was reported. Mobility (36%, 55/152) and migration or exposure (33%, 50/152) of roots were the most common underlying causes of failure. Coronectomy seems to be safe, but it depends on the patient and the technique used. To ensure adequate assessment of postoperative complications, we strongly recommend systematic evaluation of the reduction in sensitivity of the lower lip, chin, or tongue, and a standard follow up.