Retrospective evaluation of sensory neuropathies after extraction of mandibular third molars with confirmed "high-risk" features on cone beam computed topography scans

Objectives. The objective of this study was to identify the incidence of inferior alveolar nerve (IAN) injury after extraction of mandibular third molars with confirmed "high-risk" features on cone beam computed topography scans and establish any risk factors that significantly increase the chances of sustaining an IAN injury. Study Design. This study is a retrospective analysis of outcomes after surgical extraction of 500 mandibular third molars over a 5-year period. All teeth showed signs of contact with or compression of the IAN on cone beam computed topography scans. Results. The overall incidence of IAN injury was 6.6%, with permanent neuropathies accounting for 1.8% within this high-risk cohort. Statistically significant factors shown to increase the risk of nerve injury included increasing age (P = .002), compression of the nerve evident on cone beam computed topography scan (P = .005), and buccal or interradicular position of the nerve (P = .042). Conclusions. Results indicate a low incidence of IAN injury, particularly given the high-risk nature of all teeth that were extracted. It highlights the benefits of cone beam computed topography scans in surgical planning. These data are an important contribution to the existing literature and valuable in the consent procedure for patients undergoing surgical removal of mandibular third molars in contact with the IAN.