Osteonecrosis of the Jaw (ONJ)

Osteonecrosis of the jaw (ONJ) is a rare condition where a part of your jawbone pokes through your gum. The area that’s exposed doesn’t receive blood, causing it to die. People with cancer who receive IV bisphosphonate therapy are most at risk for ONJ. This rare condition tends to occur after oral surgery like tooth removal. Treatment involves removing the dead bone.


What is osteonecrosis of the jaw (ONJ)?

Osteonecrosis of the jaw (ONJ) is a rare but serious condition that causes bone cells in your jawbone to die and your jawbone to poke through an opening in your gums. Because blood can’t reach the exposed area, more of the bone dies.

Osteonecrosis is the medical term for bone death. “Osteo” means bone and “necrosis” means death. Healthcare providers also call the condition avascular necrosis. Avascular refers to blood vessels in your circulatory system. When you have osteonecrosis (avascular necrosis), something slows or stops blood flow to your jawbone tissue and it starts to die.

How common is osteonecrosis of the jaw?

Osteonecrosis of the jaw is uncommon. It affects approximately 2 out of every 100 people with cancer who receive medication that helps with bone loss and eases bone pain caused by metastatic cancer. People who don’t have cancer or who don’t take this medicine can also develop ONJ, but it’s even rarer.


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What’s the difference between osteonecrosis of the jaw and osteomyelitis?

Both ONJ and osteomyelitis cause painful bone loss. But bacteria or fungi cause osteomyelitis, which is a type of bone infection. When the infection affects your jawbone, you may have symptoms similar to ONJ. However, osteomyelitis often causes a fever — ONJ doesn’t. Healthcare providers use blood tests to check for signs of infection and diagnose osteomyelitis.

Is osteonecrosis of the jaw and osteoradionecrosis the same thing?

No. Osteoradionecrosis occurs in 3% to 10% of people who receive radiation therapy for head and neck cancers. Radiation therapy to your head or neck can destroy blood vessels that carry blood to your bones. Lack of blood leads to bone death. A tooth extraction or other invasive dental procedure after radiation therapy increases your chances of developing osteoradionecrosis.


Symptoms and Causes

What are the symptoms of jaw osteonecrosis?

If you’ve recently had a dental procedure and develop ONJ, you may have pain on the side of your mouth where the procedure took place. Some people don’t have symptoms.

Signs of ONJ include:

What causes osteonecrosis of the jaw?

ONJ tends to occur after oral surgery like a tooth removal (extraction), dental implant or dental bone graft that may leave some of your jawbone exposed. In osteonecrosis of the jaw, your gum tissue doesn’t heal after your dental procedure and your jawbone is left exposed. Your exposed bone doesn’t receive blood flow. As a result, your bone cells die. Rarely, you may develop ONJ for no apparent reason.

Risk factors for ONJ

Anyone can develop ONJ. Your risk increases if you receive antiresorptive medications called bisphosphonates. These IV (intravenous) medications slow bone loss and increase bone strength (density), helping prevent bone fractures. These medications also ease musculoskeletal pain from metastatic cancer that spreads to your bones (skeletal system) and lower your risk of fractures after receiving certain cancer treatments. Studies haven’t shown a link between lower-dose oral antiresorptive medicines for osteoporosis and ONJ.

Other ONJ risk factors include:


Diagnosis and Tests

How is osteonecrosis of the jaw diagnosed?

Your dentist or oral surgeon may diagnose ONJ based on your symptoms. It’s important to see your dentist as soon as you detect a problem, especially if you’re at high risk for ONJ. Early diagnosis and treatment of ONJ may save your jaw and teeth. An exposed jawbone that persists for more than eight weeks indicates ONJ.

What are the stages of osteonecrosis of the jaw?

There are four stages of ONJ ranging from 0 (least severe) to 3 (most severe). Your healthcare provider will determine the disease stage at the time of diagnosis.

Stages of ONJ include:

  • Stage 0: You receive IV bisphosphonate treatments and have jaw pain. However, you don’t have an exposed jawbone or other ONJ symptoms. In this stage, your healthcare provider may determine other issues such as periodontitis cause your symptoms. A different problem like periodontitis may be causing your symptoms.
  • Stage 1: Your jawbone is exposed, but you don’t have pain or other symptoms.
  • Stage 2: Your jawbone is exposed and you have symptoms, including pain, swollen gums and signs of infection.
  • Stage 3: You have all the symptoms of stage 2 ONJ and you have osteonecrosis in your sinuses and other parts of your face.

Management and Treatment

How do healthcare providers treat osteonecrosis of the jaw?

Oral surgeons and prosthodontists treat ONJ. These dental professionals specialize in managing complex dental conditions that affect your teeth and jaws. Treatments depend on the stage of the disease.

Treatments for Stage 0 ONJ

If you have Stage 0 osteonecrosis of the jaw, your healthcare provider may watch for changes. To ease symptoms, your provider may recommend:

Treatments for Stage 1 ONJ

Your healthcare provider scrapes or scrubs away the exposed dead bone cells (debridement). This treatment prevents more bone loss and helps your gums to heal over your bone. After debridement, you may take antibiotics, pain medication and a prescription mouth rinse.

Treatments for Stage 2 and Stage 3 ONJ

Your healthcare provider does surgery to remove the section of dead jawbone and any tooth that touches that section of your jaw. They also remove a small amount of healthy tissue to ensure there aren’t any lingering diseased bone cells. If you have Stage 3 ONJ, you may need sinus surgery to remove dead bone that extends into your nasal passages. After surgery, you may use a prescription mouth rinse and take antibiotics and pain medication.


Can I prevent osteonecrosis of the jaw?

Everyone should practice good oral hygiene like daily brushing and flossing and having regular dental check-ups. You may be able to reduce your risk of ONJ by having gum disease treatments.

It’s very important that your dentist or oral surgeon knows you receiving antiresorptive medications. They may be able to treat your dental issue with less invasive procedures. For example, if you need to have a tooth removed, your dentist may do a root canal instead of extracting your tooth. When possible, your provider may use less invasive treatments like a root canal instead of a tooth extraction.

Outlook / Prognosis

What is the outlook for someone with osteonecrosis of the jaw?

Early detection and treatment can keep ONJ from getting worse and helps preserve your jawbone. Most people with early stages of ONJ get better with nonsurgical treatments. Once the condition worsens, you’re at risk of losing sections of your jawbone, as well as some of your teeth.

Living With

When should I call a healthcare provider?

You should contact your healthcare provider if you have:

  • Bleeding, red or swollen gums.
  • Difficulty chewing food.
  • Jaw pain.
  • Loose teeth.

What questions should I ask my healthcare provider?

You may want to ask your healthcare provider:

  • What can I do to prevent osteonecrosis of the jaw?
  • How often should I get dental cleanings?
  • What caused osteonecrosis of the jaw?
  • What stage of ONJ do I have?
  • Do I need surgery?

A note from Cleveland Clinic

The idea of losing teeth and part of your jawbone can be scary. If you’re at risk for osteonecrosis of the jaw (ONJ) due to cancer treatments or other factors, it’s important to find a dental provider you can partner with and trust. Your dentist can help you become an expert in at-home dental care. They can also take steps to treat tooth and gum problems without increasing your risk of ONJ. You should contact your dentist anytime you experience jaw pain, loose teeth or have other unusual symptoms that affect your ability to chew, talk or swallow. Acting early may help protect your teeth, bones and gums.

Medically Reviewed

Last reviewed on 09/07/2022.

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