Osteonecrosis of the jaw Infosheet

This Infosheet explains what osteonecrosis of the jaw (ONJ) is, a rare condition related to long-term treatment with drugs known as bisphosphonates.

ONJ is a rare condition in which one or more parts of the jawbone become exposed to the inside of the mouth.
The word ‘osteonecrosis’ derives from ‘osteo’, which means bone and ‘necrosis’, which means cell death. Exposed bone has no blood supply and can therefore die (become necrotic). In the jaw the bone is only covered by a thin layer of tissue, so it can quite easily become exposed. This means the bones of the jaw are particularly prone to osteonecrosis,  particularly at the site of invasive dental procedures. Exposed, necrotic bone that does not heal within eight weeks
after identifi cation by a dentist or doctor is known as ONJ.

The causes of ONJ are not entirely clear. Long-term treatment with drugs known as bisphosphonates appears to cause increased risk of ONJ, particularly the intravenous (into the vein) type. Bisphosphonate drugs are recommended for all
patients with active myeloma.

Most ONJ cases arise after invasive dental treatments or oral surgery. This includes treatments such as dental extractions, implant placement and periodontal surgery, but not routine dental work such as fillings.

Signs and symptoms of ONJ include:

  • Non-healing of a tooth socket after extraction
  • An area of exposed bone in the mouth
  • Swelling of gums
  • A heavy or numb feeling in the jaw
  • Pain
  • Loosening of teeth
  • Discharge of pus

If you do develop ONJ, your doctor will prescribe treatment to help relieve symptoms, such as antibiotics, antiseptic mouth wash and pain-killers. As well as relieving symptoms such as infection and pain, these treatments may prevent further bone from becoming exposed, therefore slowing or stopping the progression of ONJ.

It is essential to remember how important bisphosphonates are in the management of myeloma bone disease, and to bear in mind that ONJ is a rare complication.