Osteonecrosis of the jaw

Osteonecrosis of the jaw (ONJ) is an uncommon condition, the cause is not entirely known. It involves the loss or breakdown of a small segment of the jawbone. It can be a serious condition, causing pain that is difficult to treat.

Bisphosphonates are used to treat bone disease in myeloma and other cancers. Studies suggest that treatment with bisphosphonates increases the risk of ONJ occurring. Only a very small number of people treated with bisphosphonates will get ONJ.

Bisphosphonates and ONJ

The link between ONJ and bisphosphonates is not fully understood. Bisphosphonates bind to calcium and reduce the activity of the cells (osteoclasts) that cause bone breakdown. Some studies suggest that ONJ occurs because bisphosphonates disrupt normal bone regrowth. This affects healing after trauma or injury to the tissues of the mouth.

Risk factors for ONJ:

• Monthly intravenous (IV) bisphosphonates
• Removal of teeth while having bisphosphonates
• Long term use of bisphosphonates (>12 months)
• Increases with age
• Unhealthy teeth and gums
• Smoking
• Diabetes
• Poor fitting oral appliances (like dentures)

Symptoms and signs of ONJ include:

• Pain or swelling in the mouth
• Poor healing of the gum after tooth removal
• Loose teeth
• Exposed jawbone in the mouth
• Poor healing, gum infection with discharge
• Jaw numbness or heaviness

It is important to notify your treatment team and dentist immediately if you experience any of these symptoms. If you have ONJ you may be referred to an oral surgeon with experience in osteonecrosis.

Treatment and management of ONJ:

A dental review, x-rays or other radiology may be used to diagnose ONJ. Treatments for ONJ may include:

• Antibiotics.
• Pain relief medication.
• Mouth rinses/washes.
• Minor dental work to remove injured tissue and reduce sharp edges of the bone.
• Surgery is usually avoided.
• Regular dental check-ups.
• Bisphosphonate therapy may be stopped for a period of time.
• Type and frequency of bisphosphonate therapy may be changed.

Prevention of ONJ:

Before starting bisphosphonates:

• Have a dental examination and x-ray.
• Have any necessary invasive dental work. Your dentist and treatment team will make a plan.

During bisphosphonate therapy:

• Make sure your dentist knows you are on a bisphosphonate therapy.
• Good dental/mouth hygiene – brush your teeth regularly and use a mouthwash.
• Regular dental check.
• Make sure dentures fit properly and don’t rub.
• Avoid invasive dental procedures, including tooth removal or surgery.
• Tell your treatment team about any dental work you may need.
• An experienced oral and maxillofacial surgeon and your treatment team will develop a plan if an invasive dental procedure is needed.
• Bisphosphonates may be stopped before dental treatment and re-started after the area heals.
• Routine dental treatments such as cleaning, scaling and fillings are usually okay. Check with your dentist and treatment team.
• Look out for any ONJ symptoms like pain, numbness or sore areas in your mouth.
• Report any ONJ symptoms to your treatment team.

ONJ in perspective

Bisphosphonates are very effective in treating and preventing bone disease. Your treatment team will discuss the benefits versus the small risk of ONJ occurring.