Coronectomy root retrievals: a review of 92 cases

Coronectomy has become an increasingly prescribed surgical treatment for mandibular third molars that are deemed to pose a risk to the inferior dental nerve. Retention of the roots poses a risk of need for root retrieval in the future if symptoms are present. Long-term outcomes and the symptoms that lead to root retrieval via coronectomy have not been well documented or studied, and this has understandably led to hesitation in some clinicians in offering the procedure. The current series assesses patients who have undergone root retrieval, their reported indications for removal, and the histopathologic status of the removed roots.

A total of 92 cases of root retrievals via coronectomy carried out at Guy's Dental Hospital are included in this analysis. Data were collected retrospectively from patient records regarding patient symptoms, clinical and radiographic findings, function of the inferior dental nerve, and histologic results.

The mean age of patients in the study group was 31.6 years (range 19-70 years), with a female-to-male ratio of 62:18 (77.5% female). Mean time to the second surgery for root retrieval was 17 months. In "successfully" performed coronectomies, 75.3% (61 of 81) of root pulps appeared vital histopathologically. Mucosal tenderness (39 of 81 [48.1%]) was the most common symptom leading to root retrieval.

Root retrieval after coronectomy should be based on findings from sound clinical and radiographic examinations. In the presence of obvious indications, such as an unhealed socket resulting from retained enamel or soft tissue infection after eruption of roots, then retrieval should be performed with confidence that resolution would occur. However, if the coronectomy root appears an unlikely culprit, then the clinician should consider and investigate alternative diagnoses, such as overerupted upper third molars causing trauma, temporomandibular dysfunction, and the dental status of the adjacent tooth as potential causes of symptoms.