A retrospective study analysing outcomes of the coronectomy procedure at a university dental teaching clinic in Norway.

Mandibular third molars (3M) are often associated with pathologies necessitating their surgical removal. Removal of 3M can cause injury to the inferior alveolar nerve (IAN). In coronectomy, a surgical option for 3M that present a significant risk of injury to the IAN, only the crown is removed, and the root/roots are left in situ, and may move after surgery. Methodology: A retrospective review was done to analyse the outcomes of coronectomy procedures performed at the Clinic of Oral and Maxillofacial Surgery, Institute of Clinical Odontology (IKO), University of Bergen (UiB) between 2014 and 2020. During this period, a total of 63 coronectomy procedures were performed. All 63 patients were contacted after approval from the regional ethical committee, and a total of 44 patients consented to participate in the study. Radiographic analysis was done based on panoramic radiographs (OPG), and patient records were analysed to assess which demographic and local factors were associated with root migration along with the number of post-operative complications. Results: Root migration was not associated with gender, root anatomy, or pattern of tooth impaction. Root migration was observed significantly more often in the younger age group, that is, ≤25 years. There were four reported cases of post-operative complications; two of those cases resolved with systemic antibiotics, while surgical intervention was necessary in the other two cases to remove the remaining roots. There were no reported cases of transient or permanent neurosensory disturbances.  Conclusion: Coronectomy is a viable technique to avoid nerve injury with 3M removal.