By Ahkiah AllenHoward University News Service
Some medications used to treat osteoporosis and certain cancers can cause jawbone damage.
The dental community has flagged medications containing bisphosphonate, a bone-strengthening drug, as the source. Some, such as Fosomax, Actonel and Boniva, are taken orally to prevent or treat osteoporosis. Zometa and Aredia are highly potent bisphosphonates taken intravenously to treat metastatic cancers and multiple myeloma, a cancer found in plasma cells. The medicines work as intended medically. But dentists say they do more harm than good orally. More patients are showing signs of jaw osteonecrosis, a rare condition involving severe jawbone decay. It typically follows invasive dental surgeries, such as tooth extractions and bone biopsies. “This is definitely something that needs to be watched,” said Dr. McKinley Price, an oral surgery resident at the D.C. Veteran Affairs Medical Center. “Prevention is going to be the key. Oncologists have to be on board because they are the people who prescribe the meds.”
The problem is that users do not fully heal after dental procedures. The open wound exposes bone, causing infection, fracture, severe pain and decay-the disease known as Bisphosphonate Related Osteonecrosis (BRON) . Recent discoveries linking BRON to said medications most impact those over 50, the most numerous bisphosphonate users.
They may draw some comfort, though, from knowing bisphosphates only affect jawbones. Doctors say this is due to many factors. First, patients taking bisphosphonates have compromised immune systems. Second, the jaw has a greater blood supply than any other bone in the human body. Third, bisphosphonates deposit in higher concentrations in the jaw. Fourth, the combination of chronic dental diseases, such as gum disease, and large amounts of bisphosphonates causes BRON to occur solely in the jaws.
Symptoms include swelling or infection of the jaw or gums, loose teeth, gums that don’t heal after invasive procedures, drainage and numbness or a feeling of heaviness in the lower jaw. Risk factors include diabetes, smoking, alcohol consumption and using bisphosphonate-based medications for extended time periods.
The U.S. Food and Drug Administration didn’t foresee this side effect when the drugs were tested and approved for sale. Once taken, bisphosphonate builds up and remains in one’s system for years. Complications may not appear for up to 18 months. Price is developing a new protocol for screening patients and establishing methods of BRON prevention.
Cases of BRON, first reported in 2003, have since been reported by many surgeons across the U.S. and Canada. Patients may be considered to have BRON if they meet all of the following characteristics: current or previous treatment with a bisphosphonate, no history of radiation therapy in the jaws, and exposed bone in the jaw region that has persisted for more than eight weeks. Although most cases of BRON are diagnosed after invasive oral procedures, bone decay can occur spontaneously.
BRON was first reported by Dr. Robert Marx, DDS, an oral and maxillofacial surgeon at the Miller School of Medicine, University of Miami, in Florida.