Alendronate and medication-related osteonecrosis of the jaw (MRONJ)
The risk of MRONJ (medication-related osteonecrosis of the jaw) on oral alendronate is small but real. Estimates put it well below 1 percent for patients on oral bisphosphonates for osteoporosis, much higher in cancer patients on IV forms. The strongest risk factor is tooth extraction or invasive surgery, especially in the back of the lower jaw. The right move is not to avoid dental care; it is to coordinate it. Most extractions can be done safely with the right planning, and untreated infections cause more bone damage than alendronate does.
Bisphosphonates like alendronate work by slowing bone turnover. They bind to bone and inhibit the cells (osteoclasts) that break down old bone, which is what makes them effective against osteoporosis. The trade-off is that bone also remodels and heals more slowly. In a small subset of patients, particularly after surgical trauma to the jaw, the bone fails to heal properly and a section becomes necrotic (dies), creating an exposed area that does not close.
The jaw is uniquely vulnerable because it is one of the few bones routinely subjected to invasive procedures (extractions, implant placement, periodontal surgery) and one of the few bones exposed to the outside world through the mouth. An extraction socket in a patient on long-term bisphosphonates can sometimes fail to fill in with new bone the way it normally would.
The risk is much higher with intravenous bisphosphonates used in cancer treatment (zoledronic acid, pamidronate) than with oral alendronate used for osteoporosis. For oral alendronate, the risk after extraction is real but low, especially in patients who have been on the medication for less than four years.
- Tell your dentist you are on alendronate at scheduling, not on the day of the procedure.
- Tell us how long you have been on it. The risk rises with duration, particularly past four years.
- Get any infected or hopeless teeth evaluated promptly. A tooth abscess is harder on the jaw than a planned extraction with proper precautions.
- Have routine dental work done before starting a bisphosphonate if possible. The pre-treatment optimization is one of the highest-leverage protections.
- Do not stop alendronate without instructions from your prescribing physician. Brief drug holidays are sometimes considered before major dental surgery, but this is a coordinated decision.
- Maintain meticulous oral hygiene to prevent the dental problems that lead to extractions in the first place.
- An exposed area of bone in the mouth, even if it is not painful.
- A tooth socket that is not healing weeks after an extraction.
- Persistent jaw pain in the area of a recent procedure.
- A non-healing sore on the gums that has been there more than two weeks.
- Numbness or tingling in the jaw, lip, or chin (this can be a sign of bone involvement).
General guidance is a starting point. Your specific dental plan depends on your medical history, your other medications, and what your mouth looks like in person. Schedule a consultation and we’ll walk through it.
Reviewed by Dr. Isaac Sun, DDS.
This page is general information, not medical advice. Do not start, stop, or change any medication based on what you read here. Talk to your prescribing physician and your dentist about your specific situation.