Coronectomy — Acceptable Technique for Managing High-Risk M3M

Background: Coronectomy is a technique that is an alternative to the extraction of a mandibular third molar (M3M) when the roots of the M3M are in close proximity to the inferior alveolar nerve (IAN). Objective: To address the indication, technique, and complications or outcomes associated with M3M coronectomy. Assessment: When a patient presents for M3M consultation a panoramic radiograph (PR) is routinely obtained as a component of initial assessment. Several findings on a PR are suggestive of an increased risk of an IAN injury (IANI, eg, roots crossing mandibular canal, canal deviation, darkening of roots). If an increased risk is identified, a cone-beam CT (CBCT) can demonstrate 3D spatial relationships as well as bone volume and aid in surgical plan development. CBCT findings (eg, hooked or hypertrophic root[s], mandibular canal cortical interruption) are associated with an increased risk of IANI and are indications for a coronectomy; while findings (eg, periapical periodontitis more...