MRONJ (Medication-Related Osteonecrosis of the Jaw)
Fosamax, Actonel, Aclasta, Aventis, Arendia, Didrocal, Pamisol and Novartis – these drugs are bisphosphonates and used mostly for osteoporosis.
In recent years bisphosphonates have also been used to treat cancers that have spread to bone (breast, prostate, liver, lung and kidneys), Paget’s disease and Multiple myeloma (a cancer of bone marrow), but in far larger doses than for osteoporosis.
These drugs have been very effective, but in some cases, they can cause jaw bone to die – OsteoNecrosis of the Jaw or ONJ is a serious condition with no known treatment. Mostly a tooth extraction has been the trigger to the problem, although there have been a few cases where it has resulted from denture irritation, gum disease or of unknown causes.
Although rare, osteonecrosis is possible following tooth extraction in those taking Fosamax, Actonel and the other drugs listed above. There is no way of knowing how likely this is, or which patients are most at risk, and the risk does not appear to be reduced by stopping the drugs prior to extractions.
The risk of ONJ appears to be more likely in older and medically compromised patients, particularly if they have been on the drugs for a long time and/or are on corticosteroids. Where the doses of bisphosphonates are higher (in the non-osteoporosis cases) and given intravenously, the risk is considerably greater but still reasonably low.
Now increasingly these bisphosphonates are delivered by injections, typically Prolia every six months for osteoporosis. However, the more frequent the injection, or the stronger the types of Bisphosphonates, the higher the risk of the bone dying (necrosis). This causes osteomyelitis which is very difficult to treat as the dead bone is pushed out by the body. The bacteria of the mouth infect the bone deeply as the medication slows the turnover of the bone, so a net loss of bone occurs. Very messy, painful, and life threatening.
Patients often don’t think that the injection is a medication!
Dentists are on the frontline of MRONJ early detection and prevention. Common triggers are extractions, implant placement, and oral surgery.
MRONJ Checklist for the General Dentist (Patients often do not volunteer this information unless asked clearly.)
We Ask at Every New and Recall Visit: “Are you taking any bone medications or injections for osteopenia, osteoporosis, bone cancer, or to strengthen bones?”
If YES, document:
Clinical Red Flags-Do Not Ignore
- Exposed bone
- Unexplained tooth mobility
- Delayed healing mobility (>2-3 weeks)
- Draining fistula
- Pain or swelling not explained by routine dental causes
- Radiographic sclerosis or irregular bone
Early referrals are highly desirable.
What To Do If we Suspect MRONJ
- Stop elective dental treatment in that area
- Reinforce oral hygiene
- Prescribe chlorhexidine rinse
- Antibiotics only if infection is present
- Refer promptly to oral and maxillofacial surgery
- Document findings carefully
A tooth can be nerve treated even if non-restorable above the gum; extraction is the higher risk step.
Pre-Treatment Planning and Prevention is Critical
- Comprehensive dental evaluation and treatment BEFORE starting bone loss therapy is the most effective preventive strategy.
- This includes managing caries, periodontal disease, infections, hopeless teeth, denture adjustments, and optimizing oral hygiene prior to medication therapy.
Though rare, some bone medications can affect how the jaw heals. If you notice pain, exposed bone, or an area that doesn’t heal, call us right away.”
We Document the education provided.
Patients referred for osteoporosis oncology drugs must have a full dental assessment before their first dose.
In Conclusion
Lower risk or higher risk: risk is risk! MRONJ can be extremely serious. The most conservative treatment is essential to prevent extraction (RCT, pins, bridge) rather than implants.
- Identify the medication, minimize surgical trauma, and refer early when risk is elevated.
- Educate patients of potential healing issues with bone medication and document education provided
Earlier recognition of MRONJ with earlier referral and management can improve healing and limit progression.
- Drug name (e.g., Oral: Fosamax, Actonel, Atelvia, Boniva; Injection: Prolia, Xgeva; IV: Zometa)
- Length of use
- Reason prescribed (osteopenia, osteoporosis vs. cancer)
- Oral vs. Injection vs. IV
Higher Risk
- Bisphosphonates by injection: Prolia, Xgeva, or IV: Zometa
- More than 4 years
- Cancer indication
- Steroids, chemo, diabetes, smoking
- History of MRONJ
High risk = conservative dentistry + earlier referral
Lower Risk
- Oral bisphosphonate
- >4 years use
- No steroids / chemo
General Dentist Treatment Planning Rules
- Suggest restorative or endodontic (RCT) treatment over
- Avoid elective implants in high-extraction and implant when possible risk patients
- Adjust dentures to eliminate sore spots
- Treat periodontal disease
- Get thorough written informed consent of placing implants on patient with risks
aggressively non-surgically
Reference: Gordon J. Christensen Clinicians Report April 2026 Volume 19 Issue 4
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