There are about 10,000 to 20,000 cases of osteonecrosis diagnosed in the United States each year. Osteocrenosis of the Jaw (ONJ) is a condition in which bone tissue of the jaw loses blood, leading to its death and eventual collapse. It often occurs after dental surgery or trauma in which the bone is exposed. In 2003, however, reports of bisphosphonate-associated osteonecrosis of the jaw (BON) or osteochemonecrosis began to surface.
In most cases of ONJ and BON, also known as “dead jaw”, the soft tissue around teeth and bones of the jaw recedes and exposes the jawbone, making it susceptible to infection. In severe cases, a substantial amount of the jawbone disintegrates, increasing the risk of jaw fractures.
Dead jaw may be asymptomatic in the early stages of the condition. Sometimes symptoms do not appear until the jawbone is exposed. Symptoms may include:
- Loose teeth
- Heaviness and numbness of the jaw
- Pain and swelling of the gums and jaw
- Gum and jaw infections
- Slow healing of gums
- Substantial gum loss
- Exposed bone
Since untreated osteonecrosis of the jaw can lead to irreversible joint collapse within the jaw, it is important that those experiencing the symptoms listed above consult with their doctor immediately. The earlier the onset of the disease is detected, the more treatment options the doctor will have. In cases of BON, the biophosphonate drug being used may be preventing the formation of new blood vessels within jawbone tissue, so its use should be discontinued.
Invasive dental procedures should be avoided for those receiving bisphosphonate treatment. A patient’s dentist and physician should consult with each other before initiating biophosphate treatment or dental surgery, since either can exacerbate a potential dead jaw condition.
Special care should also be taken before initiating intravenous bisphosphonate therapy for cancer patients since it has been shown that this substantially increases their risk for developing BON over those who have been treated with orally administered biphosphonates.
Biophosphonates orally administered in the U.S. include:
- Risedronate (Actonel)
- Ibandronate (Boniva)
- Alendronate (Fosamax and Fosamax Plus D)
- Tiludronate (Skelid)
- Etidronate (Didronel)
Intravenously administered bisphosphonates include:
- Pamidronate (Aredia)
- Zolendronic acid (Zometa)
- Clodronate (Bonefos)
In serious cases of osteonecrosis, some dentists may remove or “debride” the dead tissue or diseased portions of teeth or bone. But debridement and other invasive treatments are controversial since they have been found mostly to exacerbate the condition. Hyperbaric oxygen treatment (breathing pressurized, highly oxygenated air) is also controversial and has shown little or no beneficial effects.
Some dentists try to control the condition with antibiotics to prevent infections and with mouth guards to protect bone and tissue.