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)

For patients who are already receiving intravenous bisphosphonates and who show no symptoms of BRONJ, it is very important to maintain good oral hygiene and dental care so as to prevent the need for dental-related surgeries. Patients should avoid oral, bone invasive surgeries. Nonrestorable teeth can be treated by removing the crown and endodontically treating the remaining roots. It is recommended that these patients avoid placement of dental implants.

Patients already receiving oral bisphosphonates who show no symptoms of BRONJ and have taken bisphosphonates for less than 3 years are not advised to make any changes in any planned surgeries. If these patients have implants placed they should be assigned to a regular recall schedule.

For patients who have taken an oral bisphosphonate for less than 3 years and have also been taking corticosteroids at the same time, the doctor who is prescribing their oral bisphosphonates should be contacted to consider prescribing a bisphosphonate “drug holiday” for at least 3 months prior to oral surgery, if systemic conditions permit. The same treatment is advised for patients who have taken an oral bisphosphonate for more than 3 years, with or without any accompanying prednisone or other steroid. In both cases, after oral surgery is performed, the bisphosphonate should not be restarted until healing of the bone has occurred.

For patients who have an established diagnosis of BRONJ, treatment revolves around the objectives of eliminating related pain, controlling infection of the soft and hard tissue, and minimizing the progression or occurrence of bone death. As said before, BRONJ cannot be cured.

So should I not use a bisphosphonate?

The decision to use a bisphosphonate should be made after you have discussed your needs with your physician, and the alternatives that are available. Bisphosphonates are very effective in the treatment and management of cancer-related conditions, as well as in the treatment of osteoporosis and osteopenia. The use of bisphosphonates is expected to increase two and a half fold by the year 2011, as compared with the year 2004. These drugs are very effective in treating bone weakness.

The bottom line: While the above recommendations for prevention are based on expert opinions, much research still needs to be done regarding prevention of BRONJ and any possible cures. While BRONJ is rare, especially in the use of bisphosphonates in the oral form, at present there remains no cure for BRONJ, and the effects of the drugs may be irreversible and destructive.