Bisphosphonate Associated Osteonecrosis (BONJ)
Bisphosphonate Associated Osteonecrosis (BONJ):
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Bisphosphonate-Associated Osteonecrosis of the Jaw: An update for clinical practice
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Bisphosphonates are a class of drugs prescribed to help with the treatment and prevention of resorptive bone diseases such as osteoporosis. These drugs are also prescribed to help with conditions that cause bone fragility or bone destruction as a result of bone metastasis associated with breast and prostate cancers. Second and third generation bisphosphonates such as Zometa (zoledronate), Reclast (zoledronate), Aredia (pamidronate), Boniva (ibandronate), Actonel (risedronate) and Fosamax (alendronate) are the drugs most commonly seen in clinical practice that may be associated with BONJ. Second and third generation bisphosphonates inhibit enzymes that are involved with osteoclastic bone resorption. These class of drugs can be taken by mouth or intravenously. When taken parenterally (IV) the bioavailability is higher which can increase the incidence of BONJ. The literature reports the occurrence of Biphosphonate Associated Osteonecroiss to be anywhere from .08 – 20 % (a wide range) for those taking these drugs IV. The oral intake of bisphophonates reports an incidence of less than .05%. Although the occurrence of BONJ with oral bisphonates is very low, the complication is still a possibility and should be taken under consideration. Fosamax is a very commonly prescribed oral bisphosphonate that we will often come across as dental professionals.
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Clinicians Review
It’s essential for clinicians to conduct a comprehensive review of a patient's medical history, especially when bisphosphonates are involved. Determining when the medication was initially prescribed and whether it was administered orally or intravenously is critical during the first evaluation. Additionally, evidence suggests that the combined use of corticosteroids and bisphosphonates may elevate the risk of developing BONJ. While most BONJ cases are linked to invasive dental treatments like tooth extractions, there are documented incidents where it has occurred spontaneously, without any dental trigger. For patients with a record of IV bisphosphonate use, endodontic treatment is often a safer alternative to extraction. Invasive surgeries carry heightened risks for these individuals and should be avoided when feasible. If a tooth is beyond saving, it may be more prudent to remove the crown and complete root canal therapy with a proper coronal seal rather than extract it. Creating a treatment strategy for these patients should include collaboration with the individual’s physician and potentially an oral surgeon. BONJ most frequently impacts the lower jaw (mandible) and often presents with an ulcer and visible bone exposure. The affected bone can become infected, leading to discomfort and occasional swelling. Managing this condition is challenging, as it does not always respond to the same treatments used for osteoradionecrosis. Although some screening methods aim to identify patients at higher risk for BONJ, research casts doubt on their reliability and effectiveness.
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Ultimately, understanding a patient’s health background is crucial before proceeding with any dental care. Hopefully, this blog provides greater insight into bisphosphonates and aids in making informed, patient-centered treatment decisions.
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**In writing this blog, much of the information was originally published by the AAE in their Colleagues for Excellence, Fall 2012 edition