Removing wisdom teeth (the third molars) has long been considered appropriate dental treatment, whether or not the teeth are causing trouble. However, a recent review of the subject in The Cochrane Database of Systematic Reviews, Issue 2, 2005, a publication of an international organization that reviews and evaluates medical research, concluded that no reliable scientific studies support the common practice of routinely removing impacted wisdom teeth, those that don't fully emerge from the gums because there's not enough room in the jaw or because the tooth isn't angled properly. The only studies the researchers unearthed were two involving just over 200 adolescents, which looked at the question of whether removing wisdom teeth prevents crowding in the lower jaw within five years. Neither showed a significant benefit. The lack of studies on this subject was attributed to the fact that it's difficult and expensive to monitor dental patients over the 10 to 20 years it would take to assess the benefits and risks of leaving impacted wisdom teeth in place. Another obstacle: the practice of routinely removing wisdom teeth means that few adults who have retained the teeth are available for a study.
There's no doubt that impacted wisdom teeth should be removed if they do cause trouble - pain, inflammation or infection of the gums, gum and bone disease, damage to adjacent teeth and the development of cysts and tumors. This is typically done between the ages of 17 to 21 because at that age the wisdom tooth roots may not be fully formed, are softer and easier to remove, and because young people heal more quickly.
The report concluded that in the absence of strong evidence suggesting that it is better to remove impacted wisdom teeth, even though no symptoms are present, the routine practice of taking them out can't be justified. Instead, the Dutch researcher who headed the study concluded that patients who are untroubled by impacted wisdom teeth should opt out of surgery.
Andrew Weil, M.D.