Third molar

In dentistry, the third molar, also call the wisdom tooth, are "the aftermost permanent tooth on each side in the maxilla and mandible."

Extraction
Regarding extractions of asymptomatic third molars, a systematic review by the Cochrane Collaboration concluded:
 * "No evidence was found to support or refute routine prophylactic removal of asymptomatic impacted wisdom teeth in adults. There is some reliable evidence that suggests that the prophylactic removal of asymptomatic impacted wisdom teeth in adolescents neither reduces nor prevents late incisor crowding."

It is estimated that two thirds of the extractions of third molars in the United States is unnecessary.

In the United Kingdom, the National Health Service states "the routine practice of prophylactic removal of pathology-free impacted third molars should be discontinued in the NHS."