The application of decision analysis to evaluate the need for extraction of asymptomatic third molars.

A theoretical model using a decision tree is used to compare three alternative strategies: extract all third molars prior to complete root formation; extract only those third molars that become impacted; and extract only those impacted third molars that develop some associated pathology. The model used to determine the expected value of these alternative strategies depends on the probability of eruption, the type of impaction, and likelihood of developing preoperative pathology. The decision tree can be used to identify a preferred strategy either for an individual patient or for a policy recommendation under a variety of clinical conditions.