Decision analysis for lower-third-molar surgery.

The objective of the study was to identify those factors that should affect treatment planning for patients who have lower third molars, using decision-analytic techniques. Utility values based on data from 104 patients indicated that the respondents considered that postoperative complications (except mild pain and temporary paresthesia) reduced health to a greater degree than did complications following non-intervention. A decision analysis indicated that the maximum expected utility of prophylactic third-molar surgery (60.25) was lower than that for non-intervention (76.96). The decision was sensitive to changes in the probabilities of occurrence of recurrent pericoronitis (threshold = 0.52), resorption of an adjacent tooth (threshold = 0.29), loss of an adjacent tooth (threshold = 0.32), and cystic change (threshold = 0.34). These thresholds are much higher than the incidence of problems affecting the lower third molar shown by a concurrent clinical audit and literature review. This study therefore suggests that lower third molars should not be removed prophylactically.