SAN FRANCISCO — When you're seeing patients who are taking bisphosphonate drugs for osteoporosis, don't forget to look in their mouths, Dr. Steven T. Harris said at a meeting on diabetes and endocrinology sponsored by the University of California, San Francisco.
Osteonecrosis of the jaw recently was added to the precautions section of the prescribing information for all intravenous and oral bisphosphonates, so it is incumbent upon clinicians to look for this very rare complication.
“One of the things I've changed in my clinical practice in the past couple of years is that I laid in a supply of tongue depressors and I've started to look in people's mouths, which I was not routinely doing before,” said Dr. Harris of the university.
Media reports about this side effect of bisphosphonates have caught the attention of patients, some of whom raise concerns about it during visits, he added.
Though no universally accepted definition exists for osteonecrosis of the jaw, a growing consensus characterizes it as an oral cavity lesion with one or more bare bone spots, in the absence of local malignancy or radiation therapy to the head and neck. This is not the same as a patient on bisphosphonate therapy complaining of tooth pain.
“This is a look in the mouth, and there is bone where there should be normal pink mucosa,” Dr. Harris said.
Osteonecrosis of the jaw primarily has been seen in cancer patients receiving high-dose intravenous bisphosphonates therapy, usually monthly. In that population, approximately 0.5%–10% of patients may develop osteonecrosis of the jaw, a range affected by the underlying malignancy.
In patients on oral bisphosphonates, however, rough estimates suggest perhaps 1 patient per 100,000 may develop osteonecrosis of the jaw per year, he said.
The pathophysiology of this disorder is not understood.
Known risk factors for osteonecrosis of the jaw include cancer; concomitant therapies like chemotherapy, radiation, or corticosteroids; poor oral hygiene; and comorbid disorders such as preexisting dental disease, anemia, coagulopathy, or infection.
Be vigilant in patients with poor dental hygiene or procedures such as tooth pulling or teeth implants, Dr. Harris said.