Oral bisphosphonates are widely prescribed as a treatment or preventative for osteoporosis. The most commonly prescribed of these is alendronate (Fosamax®) but there are others. This medication is also given in much higher intravenous doses to cancer patients. It has been known for some time that high dosage administration of bisphosphonates is linked to ONJ. ONJ is a condition where portions of the jaw deteriorate and die. In high dose bisphosphonate users, this seems to occur as a result of dental procedures, chiefly extractions. Instead of healing from the minor trauma, the jaw injury is not repaired and eventually there is much wider injury and tissue death. It is suspected that bisphosphonates make it easier for oral bacteria to adhere to the bone that is exposed after a tooth extraction and grow into it.It is suspected that bisphosphonates make it easier for oral bacteria to adhere to the bone that is exposed after a tooth extraction and grow into it.
Until recently, the prevailing view was that the risk of ONJ to oral bisphosphonate users was negligible. Dr. Parish Sedghizadeh, an assistant professor of clinical dentistry at the University of Southern California School of Dentistry in Los Angeles then began noticing that his clinic was seeing one to four new cases of ONJ a week, compared to about one a year in the past. Puzzled at this increase, he searched the patient database at the USC School of Dentistry and found that nine of the 208 patients who were also taking Fosamax® had active cases of ONJ, about 4%. All were patients who had undergone some type of dental procedure. While this isn't a study of the general population of Fosamax® users, 4% is hardly a negligible number.
The important point here is that it's possible to prevent ONJ from occurring if everybody involved knows that oral surgery patients are taking bisphosphonates. The USC School of Dentistry now screens every patient for bisphosphonate use. Dr. Sedghizadeh has his patients use an antimicrobial rinse either for a week before surgery or for a week after surgery or sometimes for both. He says that this has proven "very, very effective." There are other possible strategies that a dentist, dental specialist or doctor can employ to minimize the risk of a patient contracting ONJ. This is only likely to happen if the dental professional knows that a patient is taking bisphosphonates or the doctor prescribing the medication knows that a patient will be undergoing a dental procedure. If bisphosphonate users aren't asked about this, it is essential that they communicate this information.
There is some controversy over just how strong a link there is between oral bisphosphonate usage and ONJ. This puts users of the drug in a difficult position; particularly those who expect to have oral surgery. If you're one of these people, the best place to start gaining a deeper understanding is to talk to your doctor or dental professional.
The findings were published in the January 1, 2009 issue of the Journal of the American Dental Association.
