Bone-Density Drugs Kill Jaws
Jul 5, 2006 | MARIE MCCULLOUGH | Philadelphia Inquirer

Across the country, dentists have begun asking patients a pointed question before deciding on treatment:

Do you take a bone-building medication such as Fosamax?

These widely used drugs, called bisphosphonates, have recently been linked to a rare side effect that causes parts of the jawbone to deteriorate and die.

The bulk of the 3,000 published cases of jaw osteonecrosis meaning "dead bone" have occurred after dental procedures, mostly in cancer patients on intravenous bisphosphonates. But the problem has also developed out of the blue in otherwise healthy people taking bisphosphonate pills to boost bone density.

"If you're going to be on this drug, make sure you really need it," said Alan Meltzer, a Voorhees, Pa., periodontist.

Since 2003, when the first 36 cases were described in a medical journal, the Food and Drug Administration has required all bisphosphonate labels to include a precaution, hundreds of lawsuits have been filed against drug makers, and expert dental groups have issued advice for managing the tens of millions of people now on the drugs.

Still, there are no good treatments for what specialists have begun calling "bisphossy jaw." Nor is it clear that quitting the drugs reduces the risk because bisphosphonates can persist for years in the bone. The incidence, variation and progression of the jaw disease are also unclear.

"What we have seen and heard from health-care givers is that more and more people are showing up with milder forms, so the true incidence rate now is anybody's guess," said John R. Kalmar, an Ohio State University oral pathologist and author of a May review article in Annals of Internal Medicine. "We're telling people to be cautious."

The advent of bisphosphonates about a decade ago was a boon for people whose bones were riddled by cancer treatment, osteoporosis or a disorder called Paget's disease. Since 1995, 191 million prescriptions have been filled for oral Fosamax, Actonel and Boniva, plus millions more for intravenous Zometa, Aredia and generic Pamidronate.

For healthy people seeking to boost bone density, the risk of jawbone death appears to be remote; the estimate from Fosamax maker Merck & Co. is less than one out of 100,000 patients per year.

On the other hand, many postmenopausal women taking the pills may not really need them. Low bone density does not automatically progress to osteoporosis, and even when it does, a debilitating fracture is not inevitable.

Crystal Baxter, a former University of Pittsburgh professor of prosthodontics who now practices in Arizona, said she is very leery of doing elective dental implants in patients who have taken oral bisphosphonates.

"The scary thing," she said, "is that these drugs are being marketed to practically every aging woman in the world."

It has become clear through trial and terrible error that trying to fix bisphossy jaw with invasive dental procedures only makes it worse.

Ruth Ann Dutton, 66, for example, went to her regular dentist after a shard of bone spontaneously broke through her gum. Although she had taken Aredia and Zometa for advanced breast cancer, the splintering of her jaw was not triggered by a dental procedure.

"He did a root canal, but it never got better," she said.

A year ago, she was referred to Meltzer, who prescribed antibiotics and antiseptic rinses.

"Right now, it's doing pretty decent," she said. "The hole is mostly closed up."

Barry Levin, an Elkins Park periodontist, said one of his elderly patients has not been as fortunate. She quit Fosamax after tooth extractions led to a diagnosis of osteonecrosis, but bone grafted to her damaged jaw has not healed properly.

"It's been a nightmare," Levin said.

Bisphosphonates build bone by tamping down the normal turnover of bone cells. Kalmar and other experts speculate that osteonecrosis develops when the drugs are too effective at suppressing bone regeneration.

Why hasn't the problem shown up after, say, hip replacement surgery? Experts say the jaws are particularly vulnerable because cells turn over faster there than in other bones. Jaws are also constantly exposed to minor trauma from chewing, and to bacteria from the mouth.