Osteoporosis Medicines and Jaw Problems

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1 Osteoporosis Medicines and Jaw Problems J. Michael Digney, D.D.S. Osteoporosis is a condition that affects over 10 million patients in this country, with the majority of those being post-menopausal women. Over the past several decades, there have been a number of medications that have been developed to treat this condition. These medicines have been very successful in improving bone density and reducing the incidence of serious medical issues such as hip and spine fractures. Unfortunately, as is the case with most medications, there are side effects that may affect a certain percentage of the population taking these medicines. As the Osteoporosis medications affect bone biology, it is not difficult to understand that these medications may in some circumstances, along with the intended effect, produce undesired complications with regard to the physiology of bone healing. Bone is not static, and is an active, living tissue, that undergoes constant turnover. In other words, your bones are always changing, with old bone constantly being dissolved, and an equal amount of new bone being laid down to replace this resorbed bone. Without delving too deeply into the physiologic details of this process, suffice it to say that this process occurs throughout your lifetime, keeping the bones strong and healthy. When a patient develops Osteoporosis, this equilibrium is no longer present, and the cells that cause the bone to be resorbed become more active than the bone cells that are laying down the new bone. Since the bone-forming cells can t keep up with the bone resorbing cells, the net result is that the bones become more porous, and the condition of Osteoporosis develops. Most of us have heard or read about jaw problems with some patients taking Osteoporosis medications. Why are the jaws singled out, and the other bones less vulnerable? The reason is that the bone of in the jaws is the most rapidly turning over bone in the body. Anything that would affect the ability of the bone to regenerate itself would most profoundly affect the bone where there is the most activity. In the jaws, the bone is also closest to the surface of the skin, and is much more prone to being exposed or damaged. The most popular medicines that are used to treat Osteoporosis are in a category known as Bisphosphonates. The most popular Bisphosphonate medications are names that most of us will recognize, such as Fosamax (Aledronate), Actonel (Risedronate), and Boniva (Ibandronate). These are normally taken orally, although there are some of these medications that are given with an intravenous regimen on a less frequent basis. These medications increase bone density by slowing down the activity of those bone cells that are resorbing the bone and making it porous. The medicine works by accumulating in the bone, where it is ingested by the resorbing cells (known as osteoclasts, for those who may remember that term from back in high school biology class). These cells now can no longer function properly, and can t resorb any more bone. So far so good; less bone resorbtion, stronger bones, right? This is true, but unfortunately the medicine is also taken in by the bone forming cells (osteoblasts), which then renders them incapable of doing what they are supposed to do, which is to lay down new bone. Not all medications used to treat Osteoporosis or Osteopenia are Bisphosphonates, and may not have the same concerns outlined above. Examples of these medications are Evista (Raloxifene), Forteo (Teriparatide), and Miacalcin (Calcitonin).

2 Why is all this bone physiology business important? When something is done which damages the bone, or in a case such as a tooth extraction where we are counting on the body s ability to be able to form new bone to fill in the empty socket left by the tooth, anything that affects bone physiology, can affect the ability of our bones to heal properly. There has been much confusion and misunderstanding regarding these medications and their potential hazards, especially with respect to dental treatment. Before talking about specific recommendations, it is important to discuss another category of Bisphosphonate patients that are in a much higher risk category than patients taking these medicines orally for osteoporosis. There are patients whom may have had cancer that has invaded the bone or may have had a type of cancer called Multiple Myeloma, which is a type of cancer of certain blood cells in the bone marrow. When cancer invades the bone, it destroys bone tissue rapidly, and this causes excessive calcium to be introduced into the bloodstream. These increased calcium levels can cause lifethreatening cardiac arrhythmias and other serious problems. To prevent this problem, these patients are often given an intravenous form of Bisphosphonate medication, which rapidly shuts down bone turnover almost completely and thus prevents excessive calcium from entering the bloodstream. The most common of these medicines are Zometa (Zoledronic Acid) and Aredia (Pamidronate). Because of the high concentration of this medicine that accumulates in the bone over time, this has a dramatic effect on the body s ability to heal bone. As if this subject is not confusing enough for patients, there has recently been a new regimen of once-a-year intravenous medications for Osteoporosis, that utilizes Zometa, which as seen above is one of the intravenous medications that can cause serious bone healing issues. This is the same medication (marketed as Reclast), but given only once a year, as opposed to when the same drug at nearly the same dosage is used on a monthly basis as is the case for cancer or Multiple Myeloma patients. This regimen has not been around long enough for us to determine if it poses any increased risks compared to the oral Bisphosphonate regimen. Although we don t have any long-term studies to back this up, so far it seems that there does not appear to be a significantly greater risk of complications with this regimen when compared to the oral Bisphosphonates. The reason why there is a concern about the bone physiology issue in patients taking Bisphosphonate medications is the risk of something called Osteonecrosis, with osteo meaning bone and necrosis meaning death. Osteonecrosis is a term to describe dead, non-healing exposed bone, which occurs almost exclusively in the jaws due to the reasons outlined above. For most patients, this concern presents itself when confronted with a situation that will require bone healing, with the most common situation being a tooth extraction. When a tooth is removed, there is a hole left in the bone from the tooth root. We are counting on the body s ability to fill in that socket with your own natural bone. Anything that would interfere with this healing process is of course a concern, and as explained above, the Bisphosphonate medications can do just that, resulting in a non-healing extraction socket, with chronic exposed bone. On occasion, minor trauma such as a small laceration from a sharp food item, or pressure from a dental prosthesis can result in an area of exposed bone as well. There are many additional factors that have to be considered when assessing risk in this regard, such as age, overall health, length of time on the medication, and the use of other medicines which may also affect bone healing The good news here is that despite the effect of the oral Bisphosphonates on bone healing, the incidence of Osteonecrosis or even delayed healing after routine tooth extractions in patients that are taking these medications is extremely low. These risks increase the longer you have been taking the medication, and if you are taking Prednisone, Methotrexate, or other similar medicines that may depress your immune system. Based on various research studies and clinical experience with patients that have developed Osteonecrosis, it is has been determined that if you have been

3 taking oral Bisphosphonate medications for less than 3 years, your risk is negligible. After 3 years of use, sufficient amounts of the medicine have accumulated in the bone to present a potential problem with bone healing. These risks, as previously noted, are still extremely low for most patients. For patients that have been taking the intravenous forms of these medicines for cancer involving the bone, or for Multiple Myeloma, the situation is far more serious. We usually try to avoid any insult to the bone such as a tooth extraction in these patients, as the incidence of poor healing and exposed bone is quite high. This is a serious problem in these patients, as the area of dead bone can enlarge, and in some cases result in fracture of the lower jaw, and in severe cases, loss of a significant portion of the lower jaw. Simply discontinuing the medication does not allow the bone to return to normal, as the half life (the amount of time it would take for ½ of the medicine to spontaneously clear from the bone) of the IV Bisphosphonates is approximately 11 years. Most oral surgeons have seen patients with this problem, and as there is not yet any way to reverse the effects of these medicines, the best that we can hope for is to keep the exposed area from getting worse, and to keep infection from occurring. Research is ongoing, and there will hopefully someday be some form of treatment to reverse the deleterious effects of these medicines, and allow some degree of bone healing to tale place, but as of now there are no effective means of reversing this condition. Patients that are preparing to receive these types of medications should be evaluated by a dentist, so that any necessary oral surgical treatment can be performed either prior to, or very shortly after the beginning of the treatment, in order to optimize healing. Stopping the medication temporarily has been shown to be of some benefit with the oral Bisphosphonates however. For this reason, if the planned oral surgical procedure is elective, it is normally advised that the patient speak to their physician about taking a drug holiday where they don t take their Bisphosphonate medication for at least 3 months prior to the procedure, and then for another 3 months after the surgery. Most physicians usually don t object to this, and it normally not affect their bone density to a significant degree. It is important to note that this applies only to those oral surgical or dental procedures that involve the bone. Routine restorative dental procedures or cleanings do not pose any greater risk, and do not require any change in their medications. If the patient is in pain, and/or the dentist or oral surgeon feels that waiting for the drug holiday period would not be in the best interest of the patient, it is certainly possible to proceed with the surgery, as long as the patient is aware that there is slight additional risk. This risk is very minimal however, as the incidence of any serious problems with healing related to Bisphosphonate use, is extremely low. I have heard many patients state that they were fearful of jaw problems from their osteoporosis medicines, and that were not going to take them anymore. I explain that these medications have probably prevented countless spine and hip fractures, and the benefit to be gained by taking these medications far outweighs the risks of jaw problems. The American Dental Association Council on Scientific Affairs has stated that Routine dental treatment generally should not be modified solely on the basis of oral bisphosphonate therapy. Despite this, there is still always a risk, and there are a number of case reports of extensive Osteonecrosis in patients on the oral medications, so this is an issue that we still take very seriously. Patients sometimes ask if there are any tests which will allow us to know if they are at increased risk for healing problems with the bone. There is a blood test called the CTX test which is sometimes helpful in predicting if the bone will be able to heal properly. The CTX test checks a marker in the blood that is used to measure bone metabolism. Given the low risk of Osteonecrosis in most patients on oral Bisphosphonates, there is still much disagreement among physicians and dentists as to whether this test is necessary in every patient taking Bisphosphonates. Your treating physician or dentist can talk to you about whether this test might be useful in your particular

4 situation. This test can be especially useful for cases where more extensive surgery is planned such as implants or multiple extractions. Osteoporosis medications are widely used, and provide an excellent benefit in keeping your bones strong. Routine dental care, even oral surgical procedures, can still be performed safely in these patients, so there is no reason to postpone any needed dental treatment because of these medications. If you are contemplating any sort of dental or oral surgical procedure, it is important that you provide your dentist or oral surgeon with accurate information regarding what osteoporosis medications you are taking, especially the name of the medication and how long you have been taking it. This way, your dentist or oral surgeon can determine the best and safest way of managing your care. Dental Recommendations for Patients Taking Oral Bisphosphonate Medications and Requiring Oral Surgery or Dental Treatment. - Know which Osteoporosis medicine you are taking, and for how long - If surgery is elective, and you have been on the Bisphosphonate medication for 3 years or more, ask your physician about a drug holiday, i.e. off the Bisphosphonate medication for 3 months before and 3 months after surgery - If you have been taking the Bisphosphonate medication for 3 years or less, there is very minimal increased risk, and surgery can proceed as normal. - Be aware that the risk is usually very low, but there is still always a risk of Osteonecrosis - Unless there is planned surgery involving bone, proceed as normal. This means that crowns, bridges, restorative dentistry, dentures, cleanings, etc,. require no special precautions. - A CTX test may be recommended by your dentist or oral surgeon if your planned procedure is extensive of if you are at higher risk for bone healing problems. - Inform your dentist or oral surgeon if an extraction site or surgical site is not healing as you think it should. - See your dentist or oral surgeon immediately if you notice any rough or jagged areas in a location that should normally be covered with soft tissue, even if there is no pain, or if you can actually see any exposed bone. Routine dental treatment generally should not be modified solely on the basis of oral bisphosphonate therapy. ADA Guidelines Dental management of patients receiving oral bisphosphonate therapy. Expert panel recommendations American Dental Association Council on Scientific Affairs J Am Dent Assoc, Vol 137, No 8,

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