What is osteonecrosis of the jaw?
"Osteo" refers to bone. "Necrosis" is the medical term for dead cells. Osteonecrosis Osteonecrosis "Osteo" refers to bone. "Necrosis" is the medical term for dead cells. Osteonecrosis is the death of bone cells. Osteonecrosis happens when something, such as a bone injury, interferes with... read more is the death of bone cells. Osteonecrosis of the jaw (ONJ) is the death of some cells in your jawbone. Many people don't think of bone as living, growing tissue but it is.
What causes ONJ?
Doctors aren't sure why people get osteonecrosis of the jaw. It can happen for no clear reason. But it's more likely after you've had:
Bisphosphonates are most often taken by mouth to treat thinning bones (osteoporosis Osteoporosis Osteoporosis is a condition that weakens your bones. Your bones become thinner and more fragile. This is called a loss of bone density. If you have osteoporosis, your bones break more easily... read more 
). Taking them this way doesn't seem to increase risk of ONJ. However, high doses given by vein may increase risk, particularly if you then have oral surgery.
