Osteonecrosis of the Jaw (ONJ) and Osteoporosis Treatments: Bisphosphonates and Denosumab
If you’ve been advised to start an osteoporosis medicine such as a bisphosphonate (e.g. alendronic acid, risedronate, ibandronate, zoledronic acid) or denosumab, you may have seen worrying information online about osteonecrosis of the jaw (ONJ).
This post explains, in practical terms:
what ONJ is (and what it looks like)
how rare it is in osteoporosis treatment
what increases risk
what to do about dental work
how denosumab is different (and why stopping it needs a plan)
For more information about osteoporosis: Understanding Bone Health and Osteoporosis
For more information about DEXA scans: What is a DEXA scan and how is it used in assessing bone health?
What is ONJ?
Osteonecrosis of the jaw (often called MRONJ: medication-related ONJ) is a condition where an area of jawbone does not heal normally and may become exposed, usually in association with dental disease or an invasive dental procedure.
Symptoms can include:
pain, swelling or infection of the gums/jaw
loose teeth
poor healing after dental work
numbness/heaviness of the jaw
(occasionally) visible exposed bone inside the mouth
Which osteoporosis drugs are linked with ONJ?
ONJ risk is mainly discussed with anti-resorptive medicines (treatments that reduce bone breakdown), including:
bisphosphonates (oral tablets or IV infusions)
denosumab (Prolia®, osteoporosis dose)
The Royal Osteoporosis Society also notes a very low/very rare ONJ risk with romosozumab.
How common is ONJ in osteoporosis treatment?
For people treated for osteoporosis (as opposed to much higher-dose treatment used in some cancer settings), ONJ is described as very rare.
It’s important to keep perspective:
the risk is substantially higher in oncology pathways using higher cumulative doses and different indications
the risk is much lower in standard osteoporosis treatment
What increases the risk of ONJ?
Most cases occur in the setting of local dental risk factors and/or an invasive procedure. Key factors include:
tooth extraction or other invasive dental procedures
active gum disease, dental infection, poor dentition
poor oral hygiene
poorly fitting dentures causing trauma
higher cumulative exposure / higher-dose settings (particularly relevant in cancer pathways)
Practical prevention: what patients should do
Before starting treatment
If you have active dental problems (pain, loose teeth, gum disease, recurrent infections), arrange dental assessment and treatment first where possible.
If your dental health is generally good, routine dental care is usually sufficient.
UK MHRA advice states: everyone with cancer should have a dental check before bisphosphonates; other patients starting bisphosphonates should have a dental exam only if they have poor dental status.
While on treatment
Maintain good oral hygiene
Attend routine dental check-ups
Report mouth symptoms early (pain, swelling, loosening teeth, non-healing sores)
What if you need dental work while on bisphosphonates or denosumab?
A common question is: “If I need an extraction, do I need to stop my osteoporosis medication?”
For most people, the approach is:
Tell your dentist you are taking (or due to start) a bisphosphonate/denosumab.
Ensure your dentist follows recognised MRONJ prevention pathways.
Do not stop medication without advice, because the osteoporosis risk-benefit balance and the timing of treatment matters, especially for denosumab.
SDCEP provides clear patient guidance for people treated for osteoporosis on anti-resorptive drugs.
Denosumab is different: do not delay or stop without a plan
Denosumab is given as a 6-monthly injection. UK safety communications report an increased risk of multiple vertebral fractures within 18 months of stopping or delaying ongoing denosumab 60 mg treatment, particularly in those with previous vertebral fractures.
So, if denosumab is being started:
it should be with a long-term plan
missed doses and unplanned stopping should be avoided
if it needs to be stopped, clinicians typically arrange a strategy to reduce rebound fracture risk
This is also why it’s best to plan dental care early, and coordinate any complex dental procedures without disrupting treatment schedules unless there is a clear, clinician-led plan.
ONJ risk with romosozumab and teriparatide
Patients sometimes assume all osteoporosis drugs carry the same ONJ risk.
Romosozumab (Evenity®): ONJ is listed as a very low/very rare risk, and the same practical dental advice applies (good oral hygiene, routine dental care, tell your dentist).
Teriparatide: ONJ is not generally considered a typical adverse effect in osteoporosis dosing, and it is discussed separately from anti-resorptive MRONJ risk in patient guidance, which focuses on bisphosphonates/denosumab (and romosozumab as a very low risk)
Read more about romosozumab: Romosozumab (Evenity®) in Osteoporosis: When and Why It Is Used
What happens if ONJ is suspected?
If ONJ/MRONJ is suspected, assessment is usually via a dentist and/or oral and maxillofacial team. Management is individualised and may involve:
pain control and infection management
mouth care measures
conservative dental approaches where possible
careful coordination with your osteoporosis clinician regarding any medication decisions
Final thoughts
ONJ is a rare complication of osteoporosis treatment, and for most patients the fracture-prevention benefits of bisphosphonates or denosumab substantially outweigh this small risk—particularly when dental health is optimised and symptoms are acted on early.
The key practical message is simple: look after dental health, inform your dentist about osteoporosis medication, and avoid stopping denosumab without a clear plan.
Trusted patient information resources
Royal Osteoporosis Society (ROS): Osteonecrosis of the jaw (ONJ)
ROS factsheet (PDF): ONJ and osteoporosis drug treatments
MHRA: Bisphosphonates and ONJ – dental precautions and symptoms to report
MHRA: Denosumab (Prolia) – vertebral fracture risk if stopped/delayed
SDCEP patient leaflet (PDF): Dental advice for patients on anti-resorptives for osteoporosis
SDCEP guidance hub (for dentists/clinicians): MRONJ prevention and management
Please note, these posts are for general information only and do not constitute medical advice. Dr Singh would encourage you to speak to your healthcare professional to be assessed and managed for your specific symptoms.