Incidence and evolution of inferior alveolar nerve lesions following lower third molar extraction

OBJECTIVES: To calculate the incidence of inferior alveolar nerve (IAN) damage due to lower third molar extraction and to describe the evolution of IAN sensitivity and the prognosis of IAN damage based on preoperative data. STUDY DESIGN: A retrospective study of 4995 lower third molar extractions in 3513 outpatients. RESULTS: Fifty-five extractions (1.1%) resulted in IAN impairment. Cox regression analysis showed age to be a risk factor for the persistence of IAN injury due to lower third molar extraction. The sensation recovery rate was higher in the first 3 months. Fifty percent of the patients showed full recovery after 6 months. CONCLUSIONS: Most cases of IAN impairment following lower third molar extraction recover within 6 months, though in some cases recovery takes more than 1 year. Older patients are at an increased risk of incomplete recovery of chin and lip sensibility after third molar extraction.