No wisdom in pulling wisdom teeth

May 1 2005

No reliable studies exist to support removal of trouble-free impacted wisdom teeth, according to a systematic review of evidence. Despite this surprising lack of data, extraction of third molars has long been considered appropriate care in most developed countries.

“Watchful monitoring” of asymptomatic wisdom teeth may be a more appropriate strategy, suggest review authors led by Dr. Dirk Mettes of Radboud University Medical Centre Nijmegen in the Netherlands. Furthermore, they add, health risks and cost-effectiveness of surgery deserve greater consideration.

“Prudent decision-making, with adherence to specified indicators for removal, may reduce the number of surgical procedures by 60 percent or more,” the authors say.

The review appears in the most recent issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

Impacted wisdom teeth can cause inflammation of the gum, gum and bone disease, damage to adjacent teeth and development of cysts and tumors. General agreement exists that removal is appropriate when pain or problems occur.

However, the benefits of surgery are much less clear when it comes to removal of disease-free impacted wisdom teeth. Despite of a thorough review of the literature, the reviewers found no data to support this treatment approach.

Mettes and his colleagues could not locate any reliable studies of routine wisdom tooth removal in adults. They found two studies of the practice in adolescents, yet together these included just over 200 participants.

The studies focused only on whether removal of wisdom teeth prevents crowding in the lower jaw within five years, and neither study revealed a significant benefit. “The conclusion drawn from [the larger] study was that the removal of impacted third molars to reduce or prevent late incisor crowding cannot be justified,” say the review authors.

However, crowding is not the problem, according to Dr. Richard Haug, of the American Association of Oral and Maxillofacial Surgeons, and coinvestigator on two current studies on wisdom teeth.

Haug, executive associate dean of the University of Kentucky College of Dentistry, says wisdom teeth that are not pulled can cause decay and inflammation of the gums.“ Getting these teeth out earlier makes sense.”

In 24 years of practice, Haug says he has found that the best time to remove impacted wisdom teeth with the lowest rate of complication is between the ages of 17 to 21. “Roots may not be fully formed and are softer, and you have a young, healthy population that heals better than an older population.”

Noting that only two studies were involved in the systematic review, he says, “It was a very elegant review with very high standards; the parameters for inclusion were wonderful but could hardly be replicated by the vast majority of studies that have appeared in the literature.”

Mettes attributes the dearth of studies to two factors: the difficulty and expense of monitoring dental changes over the requisite 10 to 20 years and the lack of adults with impacted wisdom teeth, due to the prevalence of routine removal in recent decades.

“The third molar controversy is still ongoing,” concludes Mettes. “As with all surgical procedures, the surgeon wants to do surgery, it is his or her profession. However, systematic prophylactic removal of impacted third molars is not evidence-based but only practice-based and usual care. From a patient point of view, nonsurgical treatment should be the first option in an asymptomatic environment.”