Dentists divided over removing wisdom teeth
Apr. 29, 2002

By MARIE MCCULLOUGH
Knight Ridder Newspapers

Your dentist has just advised you to have your wisdom teeth removed, even though they are not causing any problems.

Is this a word to the wise, or jumping the, er, gum?

Wisdom teeth, of course, are the molars that sit farthest back in the mouth, two in the upper jaw and two in the lower. Technically called third molars, these are the last teeth to develop, usually appearing in the late teens or early twenties — supposedly about the time wisdom shows up.

For decades, dentists and oral surgeons have urged young adults to get rid of wisdom teeth that are “impacted” — below the gum and blocked from growing in normally — in order to avoid trouble down the line.

But the wisdom of this practice has never been proven. In fact, in recent years some experts have argued that the costs and surgical risks of preemptive extraction outweigh the benefits of preventing problems that may never develop.

“Careful analyses of the published research show that routine removal of impacted or unerupted, disease-free third molars cannot be justified,” E. Preston Hicks, professor of orthodontics at the University of Kentucky, wrote in the Journal of Oral and Maxillofacial Surgery in 1999.

Because existing research is limited and inconclusive, several studies are now under way to try to resolve the controversy. The largest, sponsored by the American Association of Oral and Maxillofacial Surgeons, is following 1,000 young adults with impacted wisdom teeth to see how many of them develop problems over a five-year period. The study is in its fourth year.

But even without new data, many surgeons are taking a more conservative approach.

Mansoor Madani, an oral surgeon in Bala Cynwyd, Pa., compares this gradual shift to what has happened with tonsillectomies. The annual number of people who have had their tonsils taken out has fallen from 1.2 million in the 1960s to 400,000 today because it has become clear that, given time, many patients outgrow sore throats and other tonsil-related problems.

“I think my advice to patients is: Just because they’re impacted, you don’t have to jump on it,” Madani said. “Impacted teeth are not something to be afraid of, but to be looked at and evaluated.”

For those who reach their thirties without pain, infection, gum disease or other wisdom-teeth woes, the expert consensus is clear. Leave well enough alone, but monitor the teeth for signs of change.

Until the advent of local anesthesia around the turn of the last century, impacted wisdom teeth were rarely pulled.

Today, removal strictly for preventive reasons remains less common in countries with government-funded medical care than in the United States. Indeed, two years ago, an advisory group to Britain’s National Health Service recommended that the practice be discontinued.

The basic problem with wisdom teeth is that the modern jaw — unlike that of our prehistoric ancestors — tends to be too small to accommodate these grinders. For sure, a lucky few people never get wisdom teeth or gain a bonus set of correctly aligned, properly functioning molars. But most people wind up with at least one blocked tooth. Such a tooth may remain buried beneath the bone, or grow through the bone but not the gum, or erupt partially through the gum.

While removing impacted wisdom teeth in young adulthood is not pleasant — a few days of pain, swelling and oozing blood are almost inevitable — there are two reasons why the surgery is theoretically a good idea.

First, extraction becomes more difficult when the root is fully formed, a process that takes a few years. This, in turn, increases the risk of surgical complications such as infection, sinus trouble, damage to adjacent teeth or fillings, abnormal formation of the blood clot at the extraction site (an excruciating condition called “dry socket”), and nerve injury.

“The roots get longer and they get nearer to the nerve in the jaw, so the incidence of injuring that nerve increases (in older patients),” said Louis K. Rafetto, an oral surgeon in Wilmington, Del., who is on the Third Molar Task Force of the association of oral surgeons.

Nerve damage can cause temporary numbness or tingling of the lip, tongue, cheek, chin, gums or teeth. In rare cases, the numbness is permanent.

The other reason most experts recommend preventive extraction is that belated problems with impacted teeth are common — no one knows precisely how common — and likely to necessitate later extraction. Typical problems include decay, gum inflammation, infection and crowding of adjacent teeth.

Stephanie Scannapieco, 22, of Drexel Hill, Pa., for example, said she suffered repeated abscesses around an impacted lower wisdom tooth. After two years of “procrastinating,” she took her dentist’s advice and had both lower teeth extracted 10 days ago.

In rare cases, impacted teeth can cause cysts or even tumors.

A cyst forms when the sac that surrounds a developing tooth becomes irritated and fills with fluid. This enlargement shows up on certain X-rays but, without appropriate monitoring, the cyst can grow and push against the jaw, undermining adjacent teeth, nerves and bone.

And the scariest thing — as the extreme case of Virginia Denicola, 63, shows — is that a cyst can do all this damage without symptoms.

“I didn’t have dental X-rays as a teen-ager. I grew up in a family where if it didn’t hurt, you didn’t say anything about it,” recounted the Philadelphia grandmother. “And I never had any pain.”

Denicola’s massive cyst, which eluded detection during routine adult dental care, destroyed a portion of her jawbone. It was diagnosed seven years ago when she went to the hospital because of mysterious vomiting, facial swelling and breathing difficulty. Ultimately, Madani, her doctor, performed several major reconstructive surgeries, replacing the eroded jawbone with a titanium prosthesis and bone grafts from her hip.

Today, grateful to have nothing worse than an inconspicuous scar and a slight speech impediment, Denicola offers this advice to young adults: Don’t ignore your wisdom teeth.

“This would not have happened if I had my wisdom teeth checked as a teenager,” she said.

Still, even the experts cannot confidently say whether — much less when — impacted teeth will cause trouble. Tooth position, the severity of impaction, the quality and quantity of the overlying gum, the presence of bridges or other orthodontic devices, dental hygiene and other factors come into play.

“There are so many variables,” said William G. Flick, a University of Illinois oral surgeon who has written articles about the third molar controversy. “We don’t have good figures or all the criteria to say what the risk is.”

Indeed, Swedish researchers who asked 10 oral surgeons and 30 dentists to review 72 cases and judge the need for extraction found “a great variation ... in their judgment.”

“There was no third molar that all the observers in the two groups agreed should be extracted,” the researchers reported in 1992 in the Journal of Oral and Maxillofacial Surgery.