Impact of CBCT on treatment decision related to surgical removal of impacted maxillary third molars: does CBCT change the surgical approach?

Objectives: To assess factors influencing treatment decision for maxillary third molars referred for cone beam CT (CBCT). Parameters influencing the decision to treat and to remove either the maxillary second molar or third molar were pursued. Methods: 111 impacted maxillary third molars, clinically examined including a panoramic image, in 86 patients (mean age 26 years, range 15-55) were referred for CBCT on suspicion of pathology/root resorption in the second molar, based on information in the panoramic image. The following parameters were assessed from the patient's file, including the radiographic images: (1) third molar angulation; (2) initial treatment plan based on clinical examination and the panoramic image; (3) diagnoses based on information from CBCT; (4) treatment decision after additional CBCT information was available; (5) pre-/post-operative complications; (6) treatment of the maxillary second molar. Results: 70 cases (63.1%) underwent treatment, while 41 (36.9%) received no treatment. Change in treatment plan was registered in 65 cases (58.6%) after CBCT. In 12 cases (10.8%), treatment changed from removal of the third to removal of the second molar, while 25 (22.5%) were scheduled for removal in the initial treatment plan; but after CBCT, the decision was not to treat. If external root resorption involved the pulp of the second molar, there was an almost 17 times higher risk that this tooth was removed instead of the third molar (logistic regression analysis: odds ratio 16.8; p < 0.001). Conclusions: Findings in CBCT often changed the treatment plan. Severe external root resorption observed in CBCT was the main decisive factor for removing the second instead of the third molar.