A Narrative Review of Predictive Markers for Mandibular Nerve Injury in Third Molar Surgery

Abstract

Mandibular nerve injury (MNI) is a notable complication of mandibular third molar extraction, primarily affecting the inferior alveolar and lingual nerves. Reported incidence varies, with temporary injuries occurring more frequently than permanent deficits, which remain relatively rare. The aim of the review is to review and identify predictive markers that help assess the risk of mandibular nerve injury during third molar surgery for safer surgical planning and improved patient outcomes. Risk factors for MNI include advanced patient age, male sex, specific tooth impaction types (mesioangular, horizontal), deep impactions, and prior pericoronitis or infection. Radiographic predictive markers, identified through panoramic radiographs and cone-beam computed tomography (CBCT), include root darkening, canal diversion or narrowing, interruption of the cortical border, and close proximity of roots to the nerve canal. Surgical technique, operator experience, use of magnification, and adjuncts such as piezosurgery further influence risk. Emerging risk assessment models, incorporating clinical, radiographic, and AI-based predictive tools, offer improved preoperative stratification, while molecular and genetic markers hold potential for personalised risk profiling. Integrating these predictors enables informed surgical planning, patient counselling, and optimisation of postoperative outcomes. Future research should focus on standardisation, multicenter studies, and personalised predictive models to enhance patient safety.