Kim Painter -- USA TODAY
For decades, having wisdom teeth removed was a rite of passage - one many high school graduates squeezed in before leaving for college.
The thinking was that it was best to lose those mostly useless, ill-fitting teeth before they caused infections or other trouble. Wisdom teeth, also known as third molars, often are misaligned and impacted - fully or partly stuck below the gum line - because they emerge late, at ages 17 to 25, after the jaw has stopped growing and other teeth have filled the mouth.
"Historically, oral surgeons have had the view that it's better to take them out, better to be safe than sorry," says Richard Niederman, director of the Center for Evidence-Based Dentistry at the Forsyth Institute, Cambridge, Mass.
But parents, teens and young adults can expect a more nuanced message these days. In a nutshell: some healthy wisdom teeth may be OK to keep, as long as you undergo regular exams and X-rays to catch signs of trouble, according to the latest recommendations from the American Association of Oral and Maxillofacial Surgeons. That group represents the 9,000 surgeons who remove most wisdom teeth in the United States.
Some critics of routine wisdom tooth extraction go further: They say it's best to keep most of the teeth and avoid the risks of anesthesia and surgery.
"There might be some justification for removing 30%," says Jay Friedman, a California dentist who has been a consultant to insurers and a witness in dental malpractice cases. In a report published in 2007 in the American Journal of Public Health, Friedman called the removal of some 10 million wisdom teeth each year "a public health hazard." He focused on the harm the surgeries could cause, from infections to nerve damage.
At Friedman's urging, the American Public Health Association in 2008 adopted a policy opposing the preventative removal of wisdom teeth.
But in a position paper in 2011, the oral surgeon's group said that policy was "based on an unscientific extrapolation of data." The group laid out evidence that most symptom-free wisdom teeth were not disease-free.
"About two-thirds of the time, there's going to be some problem," most often gum disease or cavities, says Raymond P. White Jr., an oral surgery professor at the University of North Carolina.
But the surgeon's group has revised advice on truly trouble-free teeth. A web page for consumers, updated in 2012, says that "wisdom teeth that are completely erupted and functional, painless, cavity-free, in a hygienic environment with healthy gum tissue, and are disease-free may not require extraction." It says patients and doctors should discuss options, ranging from removal to regular monitoring.
That can be a complicated discussion, says Thomas Dodson, an oral surgeon at Massachusetts General Hospital, Boston. He says that while one in three wisdom teeth seen by oral surgeons is disease-free, all the teeth are healthy in just 10% of patients. So patients may be deciding whether to keep some teeth but not others.
Still, those healthy teeth pose a dilemma, he says, because there's no good evidence on whether it's better to remove or retain them. Immediate surgery has risks, he says. About one in 20 patients develops an infection, one in 100 has hard-to-control bleeding and another one in 100 loses some feeling in the lips or tongue, usually but not always temporarily, he says.
But keeping the teeth may mean a more complicated surgery later. It also means spending time and money on regular exams and X-rays. The problem, Dodson says, is that no one can predict which teeth will stay healthy.
Given that unpredictability, the best course is leaving healthy teeth alone, especially since some impacted teeth will eventually emerge, Friedman says. He also says the oral surgery group has stretched the definition of diseased wisdom teeth by including any that are surrounded by open pockets of 4 millimeters or more. While so-called periodontal pockets can collect harmful bacteria, their presence alone does not prove gums are diseased, he says.
Stuart Froum, a periodontist in New York City and president-elect of the American Academy of Periodontology, agrees. Froum says he looks for swelling, bleeding and other signs to diagnose gum disease around any tooth. When those signs appear around wisdom teeth, he says, patients may want to consult both surgeons and periodontists about whether the best course is extraction or other treatments, such as medications and trimming of tissue around the teeth.
Dodson says he talks to patients about all options but recommends extraction when signs of gum disease are present. He says most agree. Even when wisdom teeth are healthy, just 40% choose to keep them, he says.
But patients already in a surgeon's office may not be typical. Since most referrals to oral surgeons come from general dentists, one just-completed study is looking at how often and why dentists recommend young people keep or get rid of wisdom teeth.
Results have not yet been published, but the study will look at whether patients follow the advice and how they fare after two years, says researcher Greg Huang, chair of orthodontics at the University of Washington School of Dentistry.
The American Dental Association referred questions about wisdom teeth to the oral surgery group. The association's website says "every patient is unique," but wisdom teeth may need to be removed for a number of reasons. The association also says wisdom teeth that are retained should be monitored for changes.