By Dr. Randall Lawson
Bisphosphonates ? What in the world is a bisphosphonate …. It kind of sounds like something you might once have ordered at the soda counter of your local drugstore to share with your best girl. In truth bisphosphonates are a class of drugs that have been developed mainly for the treatment of osteoporosis but are also used in the treatment of some invasive forms of cancer. Bisphosphonates include such drugs as Boniva, Fosomax, Actonel, Aredia, Didronel, Reclast, Skelid , Zometa as well as the generic versions of these drugs, where available. This class of medications has been shown to increase the density of bone in those taking them, often quite dramatically. They work by altering the body’s normal mechanism of bone remodeling. Bone is in a constant state of change. New bone is constantly being formed in any given area of the body even as older, less healthy and possibly damaged bone is being removed. The normal process of this remodeling is in equilibrium- that is approximately the same amount of bone is being added as is being taken away. In people suffering from osteoporosis this equilibrium is shifted in favor of the cells that are taking away bone structure resulting in less dense, porous bones that are prone to breaking. Bisphosphonates help to reduce the activity of the cells that are removing the older bone to the point that bone density will usually increase during their use.
While these drugs have been associated with relatively few side-effects when compared to the benefits they provide, one of the more common, if not most common side-effects is a condition called Osteonecrosis of the Jaw ( ONJ ). ONJ is a condition where bone of the jaw becomes uncovered and the outer layer begins to die (Osteo=Bone and Necrosis=death or die). It is believed that the removal of old bone is also involved in healing and that by interfering with this process these drugs are causing interruptions of the bony healing of these areas. Because of the newness of these medications and the relatively recent association of ONJ to them there is a scarcity of long-term research regarding their use. For instance while most people are taking the pill form of bisphosphanate the estimates for how often this problem occurs with these patients goes from 1 in 1000 all the way to 1 in 100,000- quite a difference as you can see. We do know several general characteristics of this malady and these follow. People receiving injection or IV forms of the drugs (normally used in this manner for cancer treatments) are far more likely to develop this problem and develop it earlier in their treatment. Those taking the oral ( pill ) form are usually considered safe until they have been receiving treatment for at least two years. Most cases are associated with an oral surgical procedure although some cases have occurred spontaneously or as a result of poorly fitting dentures rubbing raw spots on the jaw. The following risk factors have also been found to be associated with this affliction: increased age (greater than 65), periodontal disease, diabetes and smoking. There is also currently no effective treatment for this problem so prevention is our main focus. Before beginning therapy with one of these drugs it is important that you be checked by your dentist and any potentially problem teeth should be dealt with to limit the possibility of the need for extraction later in treatment. Extraction of problem teeth should be a consideration at this point. Some practitioners recommend a 3 month vacation from the drug but the effects continue long after discontinuing treatment making this option of little value.
Typically a patient with ONJ would have a reddened area of swollen gum tissue surrounding a protruding piece of dead bone. Surprisingly, most of these cases are not as painful as one might expect unless there is some accompanying infection. Sometimes the protruding bone may have sharp edges which can be smoothed off for comfort to the tongue. Otherwise treatment is just with antibiotics and pain medications as needed and careful cleansing of the area to keep damage to a minimum. Most cases wind up just remaining a chronic source of irritation to the patient-more of an annoyance. However, this condition can result in tooth loss, nerve damage and possible fracture of the jaw making it quite important to avoid if at all possible.
If you are currently on one of these medications it is imperative that you inform your dentist before any sort of surgical treatment is considered. If you are being advised to start please be sure to visit your dentist before starting treatment so that any needed treatment might be accomplished beforehand as once again an ounce of prevention is worth well more than a pound of cure. Until we have an effective treatment for this condition we must learn to cope with its effects.
Any questions you might have can be answered on our website www.collegeavenuedental.com or the website of the American Dental Association- www.ada.org. Thanks for reading