Osteoporosis Medications: Understanding Bisphosphonates and the Real Risk of Jaw Necrosis

When you’re prescribed a medication to protect your bones from breaking, the last thing you expect is to hear about a rare but scary side effect: jaw necrosis. It sounds alarming. And it’s true - bisphosphonates, the most common drugs used to treat osteoporosis, have been linked to a condition called medication-related osteonecrosis of the jaw (MRONJ). But here’s the truth most people don’t hear: if you’re taking these pills for osteoporosis, your risk of developing this condition is extremely low - lower than being struck by lightning.

What Exactly Is MRONJ?

MRONJ isn’t just any jaw problem. It’s when the bone in your jaw becomes exposed and doesn’t heal for more than eight weeks. It can happen after a tooth extraction, gum surgery, or sometimes even without any obvious trigger. The jawbone loses its ability to repair itself because the medication shuts down the cells that normally break down and rebuild bone - osteoclasts. This is exactly what doctors want when treating osteoporosis: slow down bone loss. But in the jaw, where bone turns over ten times faster than in your hip or spine, this same mechanism can backfire.

It’s not caused by poor dental hygiene alone, but poor dental health combined with these drugs increases the risk. Think of it like this: if your gums are already inflamed or you have an infected tooth, and your body can’t heal properly because of the medication, the infection can spread to the bone. That’s when things get serious.

Bisphosphonates: The Good, the Bad, and the Misunderstood

Alendronate (Fosamax), risedronate (Actonel), and ibandronate (Boniva) are oral bisphosphonates. They’ve been around for decades. Since the 1990s, they’ve helped millions of older adults avoid broken hips and spinal fractures. The data is clear: alendronate cuts hip fracture risk by over 50% and spine fractures by nearly 50% over just a few years. That’s not a small win - it’s life-changing.

But here’s where the confusion starts. People hear “osteonecrosis of the jaw” and think it’s common. It’s not. For someone taking oral bisphosphonates for osteoporosis, the risk is about 0.7 cases per 100,000 people per year. That’s less than one in a hundred thousand. Compare that to cancer patients on high-dose IV bisphosphonates - their risk is 100 to 1,000 times higher. Why? Because they’re getting much stronger doses, often monthly, for years.

Even then, most cases happen in people who had dental work done while still on the drug - especially tooth extractions. A 2023 survey found that 63% of MRONJ cases in osteoporosis patients followed a dental extraction. That’s why dentists now ask: “Are you on osteoporosis meds?” before pulling a tooth.

Denosumab vs. Bisphosphonates: Which Is Riskier?

Denosumab (Prolia) is a newer drug, approved in 2010. It works differently - instead of targeting bone cells directly, it blocks a protein that activates them. It’s just as good at preventing fractures. But here’s the twist: multiple studies now show denosumab carries a higher risk of MRONJ than oral bisphosphonates. About 1.7 to 2.5 times higher. That’s not because it’s more dangerous overall - it’s because it works faster and more completely to stop bone turnover. And when you stop it, your bone can rebound quickly, which can lead to sudden, severe bone loss if you’ve had dental work.

That’s why doctors now advise: if you’re switching from bisphosphonates to denosumab, get your dental work done first. And if you’re coming off denosumab, wait at least three months before any major dental procedure.

Who’s Really at Risk?

Not everyone who takes these drugs will get MRONJ. In fact, most won’t. But certain factors raise the risk:

• Having gum disease, tooth decay, or loose teeth before starting the medication
• Getting invasive dental work - especially extractions - while on the drug
• Being on IV bisphosphonates (like zoledronic acid) for more than three years
• Smoking or having diabetes - both impair healing
• Using steroids long-term

Here’s something surprising: a 2011 study of 260,000 osteoporosis patients found no increased risk of jaw necrosis in those taking oral bisphosphonates compared to people not taking them at all. That’s right - the risk might be no higher than if you never took the drug. But if you have poor oral health? That’s when the numbers climb.

What Should You Do Before Starting or Continuing Treatment?

If you’ve been told you need bisphosphonates for osteoporosis, here’s your action plan:

1. See your dentist before you start the medication. Get a full exam. Fix cavities, treat gum disease, remove teeth that are failing.
2. Keep your teeth clean. Brush twice a day, floss daily. Use a soft-bristled brush if your gums are sensitive.
3. See your dentist every six months. Even if you feel fine. Early signs of MRONJ - like a small piece of bone sticking out or a sore that won’t heal - are often painless at first.
4. Tell your dentist you’re on bisphosphonates or denosumab. Don’t assume they know. Bring your prescription list.
5. Avoid invasive procedures like implants or extractions unless absolutely necessary while on the drug.

If you’ve already been on bisphosphonates for years and haven’t had dental issues, don’t panic. The longer you’ve been on the drug without problems, the lower your risk becomes. The jawbone doesn’t suddenly turn to dust after five years - it’s a slow process tied to trauma and infection.

Drug Holidays: Do They Help?

Some doctors suggest stopping bisphosphonates for a few months before major dental work - a “drug holiday.” But it’s not simple. A major 2024 study found that stopping IV zoledronic acid for more than a year cuts MRONJ risk by 82%. But it also increases your fracture risk by 28%. That’s a huge trade-off.

For oral bisphosphonates, the data isn’t as clear. Most experts don’t recommend stopping them unless you’ve been on them for five years or more and have no other risk factors. The fracture protection lasts long after you stop taking the pill - sometimes for years - because the drug sticks to your bones. So stopping might not even help much.

Real Stories, Real Fears

One woman in Adelaide, 68, told her story online: after five years on alendronate, a routine cleaning revealed exposed bone. It took 18 months of antibiotics and surgery to heal. She’s now off the drug and says she’ll never go back.

Another man, 72, has been on Fosamax for 22 years. He’s had multiple extractions and two dental implants. Zero problems. His dentist says he’s the exception.

These stories aren’t contradictions - they’re reminders that risk isn’t the same for everyone. Your oral health, your lifestyle, your medical history - they all matter more than the drug name.

What’s Next?

The field is moving toward smarter treatment. Researchers are testing blood and urine markers to predict who’s at highest risk for MRONJ. In the next few years, we might see doctors use simple tests to decide: “You’re low risk - stay on bisphosphonates.” Or: “You’re high risk - switch to a different drug or take a break.”

For now, the message hasn’t changed: bisphosphonates save lives by preventing fractures. The risk of jaw necrosis is real - but it’s rare. And it’s almost always preventable with good dental care.

If you’re on one of these drugs and worried, talk to your doctor and your dentist together. Don’t stop the medication on your own. Don’t avoid the dentist out of fear. And don’t let a rare side effect scare you away from a treatment that could keep you walking, standing, and living without a broken hip.

Key Takeaways

• MRONJ is extremely rare in people taking oral bisphosphonates for osteoporosis - less than 1 in 100,000 per year.
• Denosumab carries a higher MRONJ risk than oral bisphosphonates, but both are far safer than the risk of a hip fracture.
• Most cases happen after dental extractions in people with existing gum disease or infection.
• Good oral hygiene and pre-treatment dental exams are the best way to prevent MRONJ.
• Stopping bisphosphonates to avoid MRONJ often increases fracture risk more than it reduces jaw problems.

Frequently Asked Questions

Next Steps

• If you’re not on bisphosphonates yet: Schedule a dental checkup before starting.
• If you’re currently on them: Book your next dental cleaning. Ask your dentist to check for exposed bone or slow-healing areas.
• If you’ve had a tooth pulled recently and your jaw isn’t healing: See your dentist immediately. Don’t wait.
• If you’re scared to take the medication: Talk to your doctor. Ask: “What’s my personal fracture risk? What’s my personal MRONJ risk?” Numbers help calm fear.