Osteonecrosis of the jaw is a condition where bone tissue in the jaw dies because it can no longer repair and renew itself. The bone becomes exposed through the gums and fails to heal, typically for eight weeks or longer. It is most commonly linked to certain medications used to treat osteoporosis or cancer that has spread to the bones, which is why the condition is often called medication-related osteonecrosis of the jaw, or MRONJ.
How Jaw Bone Dies
Your bones are constantly breaking down and rebuilding. Specialized cells called osteoclasts dissolve old bone, while other cells lay down new bone to replace it. This cycle keeps your skeleton strong and allows injuries like tooth extractions to heal normally.
Certain medications deliberately slow or stop this breakdown process. Bisphosphonates, commonly prescribed for osteoporosis and bone cancers, work by killing osteoclasts. Another drug class achieves a similar result by preventing new osteoclasts from forming in the first place. The goal is to reduce dangerous bone loss elsewhere in the body, but the jaw is uniquely vulnerable to a side effect: when bone turnover grinds to a halt there, damaged or aging bone can’t be replaced. Over time, patches of jaw bone lose their blood supply and die.
The jaw is more susceptible than other bones because it experiences constant stress from chewing and because dental procedures like extractions create wounds that depend on healthy bone remodeling to close. When the renewal process is suppressed, those wounds stay open, and the bone underneath begins to deteriorate.
Who Is at Risk
The biggest factor is which medication you take and how you take it. Patients receiving intravenous bisphosphonates for cancer-related bone disease face the highest risk, with reported rates between 1% and 10%. By contrast, people taking oral bisphosphonates for osteoporosis have a much lower risk, estimated between 0.001% and 0.01%. The difference comes down to dose and potency: IV formulations deliver far more of the drug directly into the bloodstream.
Beyond medication type, several other factors increase vulnerability:
- Dental surgery. Tooth extractions are the single most common trigger. The empty socket requires robust bone healing, which suppressed bone turnover can’t deliver.
- Duration of treatment. The longer you’ve been on bone-modifying medications, the more your jaw’s remodeling capacity is reduced.
- Poor oral health. Gum disease, dental infections, and ill-fitting dentures create chronic irritation that demands ongoing bone repair.
- Other medications. Corticosteroids and certain cancer therapies that affect blood vessel growth can compound the risk.
Early Warning Signs
One of the trickiest aspects of osteonecrosis of the jaw is that the early stages don’t always hurt. Bone can weaken and begin to die without causing pain, which means some people don’t notice a problem until the condition is more advanced.
The hallmark sign is exposed bone visible through the gums that persists for more than eight weeks. Before that becomes obvious, you may notice a feeling of numbness or heaviness in the jaw, sometimes described as a general unpleasant or abnormal sensation. Other symptoms include loose teeth that weren’t loose before, swelling and tenderness of the surrounding soft tissue, and drainage or pus near the affected area. If you’re on a bone-modifying medication and a tooth extraction site isn’t healing as expected, that’s a significant red flag.
How It Is Diagnosed
Dentists and oral surgeons typically identify the condition through a combination of clinical examination and imaging. A panoramic X-ray of the jaw can reveal areas where the bone has become abnormally dense (sclerotic), zones of bone destruction, or fragments of dead bone separating from living tissue. Tooth sockets that remain visible on imaging long after an extraction are another telling sign.
CT scans provide a more detailed picture, showing increased density in the bone marrow, reactions along the outer bone surface, and the extent of any dead bone fragments. The clinical definition requires exposed bone lasting more than eight weeks in a patient who is taking or has taken bone-modifying medications and has no history of radiation therapy to the jaw, since radiation can cause a similar condition through a different mechanism.
Treatment Options
Treatment depends on how far the condition has progressed. In mild cases where bone is exposed but there’s no infection or pain, the approach is often conservative: antimicrobial mouth rinses to keep the area clean, close monitoring, and avoiding any dental procedures that could make things worse. The goal is to prevent the exposed bone from becoming infected.
When infection is present, antibiotics become part of the plan alongside regular rinses. For more advanced cases involving significant bone death, pain, or fracture, surgery to remove the dead bone may be necessary. Surgeons sometimes remove the surrounding socket bone (a procedure called alveolectomy) to reach healthy tissue and encourage proper healing. In one study of 102 extractions in high-risk patients, combining this surgical technique with antibiotics and antimicrobial rinses prevented osteonecrosis from developing in every case over a 12-month follow-up.
Recovery timelines vary widely. Small areas of exposed bone in otherwise healthy tissue can sometimes stabilize or even resolve with conservative care over months. Larger areas requiring surgery may need a longer recovery, and some patients deal with recurring episodes.
Reducing Your Risk Before Problems Start
The most effective strategy is prevention, and it starts before you begin taking bone-modifying medications. A thorough dental exam to identify and treat any existing problems, such as infections, teeth that need extraction, or gum disease, significantly lowers the chance of osteonecrosis developing later. Completing necessary dental work while your bone remodeling is still functioning normally gives extraction sites time to heal properly.
Once you’re on medication, maintaining good oral hygiene becomes even more important. Regular dental checkups allow your dentist to catch small issues before they require invasive treatment. If you do need a tooth extracted, let your dentist and prescribing doctor know about your medication so they can coordinate the safest approach. Some clinicians consider a temporary pause in medication before dental surgery, though the benefit of this “drug holiday” remains debated and depends on how long you’ve been taking the drug and what condition it’s treating.
Removable dentures deserve special attention. Poorly fitting dentures create pressure points on the gums and underlying bone, which can trigger the same kind of damage as a surgical wound. Having dentures adjusted regularly reduces this risk.