Bisphosphonates are medications used to treat diseases which result in weakened bones; most commonly these diseases include osteoporosis, osteopenia, or bone cancer. Bisphosphonates typically remain in the bones for a long time after they are used—from decades to a lifetime. Fosamax (Alendronate), Actenol (Risendronate), and Boniva (Ibandronate) are the oral forms of this drug, and are used most commonly for osteoporosis. Zometa (Zolendronic acid) and Aredia (Pamidronate) are the intravenous forms, most commonly used to treat cancer involving the bones.
Fosamax and Actonel are the most commonly prescribed bisphosphonates, with about 23 million combined prescriptions in 2003. Aredia and Zometa are far more uncommonly used. Bisphosphonates are very effective in helping to prevent fractures of the hips and backbones associated with osteoporosis. They are also very helpful in preventing fractures and pain associated with cancer in the bones.
What is their relationship to teeth, and what is jawbone death?
Bisphosphonates appear to slow the natural process of removal and replacement of bone, which for the repair process of bone in the jaws is vital; this change in rate of healing of the jaw appears to be related to jaw bone death. Jaw bone death results in pain, changes in bone structure that can be seen via x-ray, spicules of bone protruding through the gums or skin, sloughing of pieces of bone, and sometimes drainage of pus. In 2004, the first cases of bisphosphonate-related jawbone death were reported; by 2007, there were over 4000 reported cases.
What are the risk factors for BRONJ?
The following factors are risk factors for Bisphosphonate-related jaw bone death (BRONJ): the use of intravenous forms of bisphosphonates (which have a greater risk factor than the use of oral bisphosphonates, though there is still a risk with oral use), long-term bisphosphonate use, extractions or gum surgery, naturally sharp bones of the jaw, dental infections, age, concurrent cancer, concurrent osteoporosis.
The following factors are thought to be contributing risk factors for BRONJ: Corticosteriod therapy, diabetes, smoking, alcohol use, poor oral hygiene, and chemotherapeutic drugs.
Most BRONJ cases are associated with the use of intravenous forms of bisphosphonates (in as many of 12% of people using the intravenous forms). BRONJ seems to occur less in those taking the oral forms of bisphosphonates, estimated at 1 in 100,000 people per year.
BRONJ can occur spontaneously, for no reason, but is often associated with abscessed teeth or periodontal (gum) disease. In other words, people who are taking bisphosphonates can develop BRONJ without having a dental procedure, but they have more of a risk of developing BRONJ if they have certain oral conditions. BRONJ can be associated with dental procedures, including extractions, root canals, gum surgery, and implants. One study suggests that people on Fosamax have between a 1 in 300 and 1 in 1100 chance of developing BRONJ after an extraction. A study of about 120 cases of BRONJ, 40% were associated with having a tooth removed.
How can I prevent BRONJ?
Prior to starting bisphosohonates, or within the first 3 years of being on bisphosphonates, getting your mouth in great shape and removing any problematic teeth is felt to be prudent. An evaluation by your dentist can help you plan extractions, root canals and gum procedures before being on a bisphosphonate, before there may be a risk for developing BRONJ.
After being on bisphosphonates for more than 3 years, if systemic conditions permit, a “drug holiday” of 3 months before and 3 months after a procedure may be helpful. This should all be done in consultation with your physician.
Can BRONJ be treated?
At present, there is no cure for BRONJ: only treatment to reduce infections, remove sharp areas of exposed bone, and prevent progressive loss of other teeth. As said before, BRONJ has no cure, and the sloughing of bone can be ongoing.
Treatment strategies having to do with oral surgery:
- For patients about to start intravenous bisphosphonates, non-restorable teeth or bad teeth should be removed. This is because the majority of people experience BRONJ after dental-related surgeries. Also, if systemic conditions permit, the bisphosphonate therapy should be delayed until the extraction site is healed (mucosalized)