Predictors of surgical difficulty in upper third molar removal: a prospective cohort study.

Background: Upper third molar (U3M) removal is a common surgical procedure. The aims of this study were to assess the patient-specific, radiological and surgical factors related to the difficulty of U3M removal, and to determine the incidence of intraoperative and postoperative complications.

Material and methods: A prospective cohort study was carried out in adult patients undergoing U3M removal. Operative time, surgeon-reported difficulty and the Parant classification were used to assess extraction difficulty. Clinical, radiological and surgical factors were recorded to determine their relationship with surgical difficulty. A descriptive, bivariate and multivariate statistical analysis was carried out.

Results: A total of 250 patients were included. The mean operative time was 10.4 (±12.3) minutes, mean surgeon-reported difficulty was 3.2/10 (±2.3). The multivariate analysis showed greater impaction against the second molar and greater soft tissue and bony impaction to significantly increase operative time and surgeon-perceived difficulty. Additionally, surgeon experience was related to perceived difficulty. The overall incidence of intraoperative complications was 0.8%, and no postoperative events were recorded.

Conclusions: Upper third molars in close relation with the roots of the adjacent second molar and with soft tissue and bony impaction are significantly more difficult to extract. Perceived difficulty was related to surgeon experience. This procedure appears to produce few intra- and postoperative complications.