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Second science forum spotlights ONJ

The second Open Clinical and Science Forum, held Oct. 18 at Moscone West, attracted roughly 1,000 dentists and others to a discussion of one of dentistry’s hotter topics: Medication-associated osteonecrosis of the jaws.

The first installment of the 2012 science forum, held the day before, focused on screening for medical conditions in the dental office. Now in their third year, the science forums continue to spotlight major, sometimes controversial issues in dentistry and are hosted by the ADA Council on Scientific Affairs and The Journal of the American Dental Association.

Dr. Cesar Migliorati, director of oral medicine at the University of Tennessee, was one of four panelists recruited for their expertise on issues related to osteonecrosis of the jaw.

Dr. Migliorati provided a general overview of ONJ, focusing on the diagnostic process and patients at risk, including cancer patients with bone metastasis, osteoporosis patients taking medications to curb fractures, and patients with an extended history of taking bisphosphonates and other drugs associated with ONJ.

The longer a patient takes an ONJ-related medication, "the higher the risk," he said.

Dr. Sook-Bin Woo, an associate professor at the Harvard School of Dental Medicine, described the two prevailing theories of ONJ—inside-out and outside-in.

As the name suggests, the inside-out theory says osteonecrosis starts within the bone and moves outward. The second theory is that the disease begins outside—for example, in the epithelial cells—and moves inward.

Dr. Woo said ONJ is probably too complex to be explained by either theory.

"Is it possible," she asked, "that one mechanism may predominate over another in different patients? We don’t know."

Dr. Thomas Dodson, professor of oral and maxillofacial surgery at the Harvard School of Dental Medicine, zeroed in on whether bisphosphonate-related ONJ can be prevented.

He talked about the value of drug holidays and about biomarkers, including serum CTX testing, which he declared "has little or no value."

Dr. Joan Otomo-Corgel a clinical professor at the UCLA School of Dentistry, focused chiefly on effects of osteoporosis. She reported that 40 percent of white females and 13 percent of white males over 50 years old would experience at least one clinically apparent "fragility-associated" fracture in their lifetime.

She said osteoporosis is prevalent in the jaws because of a rapid turnover in bone (more than three times faster in the mandible than in the tibia) and because the overlying mucosa is thin.

Judging by the volume of questions from the audience, ONJ was a popular forum topic.

As the meeting neared its conclusion, JADA’s Dr. Glick posed a question of his own, a hypothetical:

"A 60-year-old female who’s been on bisphosphonate therapy for three years enters your office in need of an extraction. Do you do it?"

He asked for a show of hands. Only a very few dentists in a very large audience raised their hands. But all four of the panelists raised theirs—they would extract the tooth without reservation, they said, after assessing comorbidities.

"Patients seek our help, and we have to balance risk and benefit," said Dr. Glick. "Available data indicate that for the patient taking bisphosphonates, the benefit of treatment greatly outweighs the risk, even for such invasive procedures as extraction."