The criteria for lower second molar extraction.

The benefits of lower second molar extraction are substantially reduced if the third molar fails to erupt into a satisfactory position. The selection criteria offered by the literature have been tested in a sample of 51 patients. Prediction is uncertain and cases should be followed until such time as a satisfactory third molar position has been achieved. Failure may be unilateral and more often on the right side. The need for follow-up treatment is subjective but may be as many as one in five patients.