Osteonecrosis of the jaw (ONJ) starts with subtle changes that many people dismiss for weeks or months before the hallmark sign appears: exposed bone in the mouth that refuses to heal. By the time bone is visible through the gums, the disease has already progressed beyond its earliest stages, which is why recognizing the warning signs that come before exposed bone matters far more than identifying the condition once it is obvious. The visual progression runs from faint soft-tissue changes all the way to draining fistulas and large sections of dead bone, and understanding what each stage looks like can mean the difference between a manageable problem and one requiring major surgery.
What Osteonecrosis of the Jaw Actually Looks Like
The defining visual feature of ONJ is nonhealing exposed bone in the mouth or jaw area. In clinical photographs, this typically appears as a patch of whitish or yellowish bone visible through an opening in the gum tissue, most often along the lower jaw. The surrounding gums are usually red, swollen, and sometimes pulling away from the bone. In early cases, the exposed area might be no larger than a pencil eraser. In advanced cases, it can span several centimeters and involve the entire ridge of the jawbone.1PubMed. Bisphosphonate-related osteonecrosis of the jaw: a pictorial review
As the disease progresses, the bone itself changes appearance. Early exposed bone looks relatively smooth and pale. Over time, it becomes rougher, darker, and may develop a grayish or brownish discoloration as the dead bone tissue deteriorates. In the most severe presentations, bone fragments can loosen and separate on their own, a process called sequestration. Advanced imaging studies describe cases featuring draining fistulas, where pus tracks from the infected jawbone through the skin of the chin or neck, creating visible openings on the face.2Journal of Oral and Maxillofacial Surgery. Imaging Findings for Bisphosphonate-Associated Osteonecrosis of the Jaws
Warning Signs That Appear Before Exposed Bone
The most important visual clues show up before bone becomes visible. These early warning signs are precisely what people should be watching for, because this is the window when intervention works best. The trouble is that many of these signs mimic routine dental problems, which is why they get overlooked.
The earliest symptoms to watch for include:
- Persistent jaw pain: A dull ache or soreness in the jaw that does not resolve within a few weeks, sometimes described as a toothache without an obvious dental cause.
- Swollen or boggy gums: Soft tissue over the jawbone that looks puffy, inflamed, or darker red than surrounding tissue, particularly along a tooth extraction site or around a denture pressure point.
- Numbness or heaviness: A strange sensation in the lower lip or chin, sometimes described as partial numbness or a feeling of heaviness. This suggests the nerve running through the lower jaw is being affected.
- A tooth socket that won’t close: After an extraction, the gum normally fills in within a few weeks. A socket that remains open, raw, or continues to ooze after two months is a red flag.
- Loose teeth with no explanation: Teeth becoming mobile in an area of otherwise healthy gums, especially in someone taking bone-targeted medications.
- Bad taste or smell: A persistent foul taste or odor from a specific area of the mouth, even with good hygiene, can indicate infected bone beneath the gum surface.
These signs become especially concerning in anyone taking antiresorptive drugs like bisphosphonates or denosumab. A review in the dental literature noted significant underreporting and misdiagnosis of these cases in everyday clinical practice, with many physicians underaware of this complication.3PubMed Central. A Narrative Review of Osteonecrosis of the Jaw: What a Clinician Should Know That means patients themselves often need to be the first line of detection.
Why the Jaw and Not Other Bones
The jaw is uniquely vulnerable for reasons that have to do with its blood supply and how much biological work it does compared to other bones. Medications like bisphosphonates slow down bone turnover by increasing the death of osteoclasts, the cells that break down old bone so new bone can replace it. This slowed remodeling leads to the buildup of old, brittle, hypermineralized bone that cannot repair itself when damaged. Meanwhile, the jaw has a high metabolic rate because of the constant stress of chewing and because the thin layer of tissue covering it leaves it more exposed to bacteria and minor trauma than bones elsewhere in the body.4International Journal of Oral Science. Pathogenesis and multidisciplinary management of medication-related osteonecrosis of the jaw
Some of these drugs also impair blood vessel growth in the jaw, further starving the bone of the nutrients it needs to heal after any disruption. This combination of reduced bone turnover, poor blood supply, and constant exposure to mouth bacteria creates the perfect storm for osteonecrosis in the jaw specifically.
Which Medications Put You at Risk
Not all medications carry the same level of risk. The drugs most closely linked to jaw osteonecrosis fall into a few categories, and the risk varies dramatically depending on the route of administration and the underlying condition being treated.
Intravenous bisphosphonates, the kind typically given to cancer patients to manage bone metastases, carry the highest risk. One review found that roughly 94% of reported cases involved patients receiving intravenous bisphosphonates, compared to about 6% on oral formulations.5PubMed. Osteonecrosis of the jaw in patients receiving intravenous or oral bisphosphonates The estimated risk for intravenous users ranges from about 0.9% to 3.1%, versus just 0.01% to 0.04% for oral bisphosphonate users, and risk climbs with longer treatment duration.6British Journal of General Practice. Why worry about bisphosphonate-related osteonecrosis of the jaw? A guide to diagnosis, initial management, and referral of patients
Denosumab, another widely used antiresorptive drug, also carries risk. The picture here is nuanced: one large real-world study of osteoporosis patients found the incidence of ONJ was about 28 per 10,000 patient-years in denosumab users compared to roughly 5 per 10,000 patient-years in bisphosphonate users, and the risk was higher if someone had previously been on bisphosphonates before switching.7Journal of Bone and Mineral Research. Risk of Osteonecrosis of the Jaw Under Denosumab Compared to Bisphosphonates in Patients With Osteoporosis However, a Taiwanese study found that over longer timeframes, the ONJ risk from denosumab in osteoporosis patients was actually lower than that from bisphosphonates.8PubMed Central. Risk comparison of osteonecrosis of the jaw in osteoporotic patients treated with bisphosphonates vs. denosumab: a multi-institutional retrospective cohort study in Taiwan The discrepancy likely reflects differences in study populations and how prior bisphosphonate use was accounted for.
Newer cancer drugs have added another layer of concern. Patients receiving both a bone resorption inhibitor and a vascular endothelial growth factor receptor inhibitor (a type of targeted cancer therapy) face a roughly five to ten times higher risk of ONJ than those on bone drugs alone, with an overall incidence around 11%.9PubMed. Incidence of medication-related osteonecrosis of the jaw in patients treated with both bone resorption inhibitors and vascular endothelial growth factor receptor tyrosine kinase inhibitors Certain protein kinase inhibitors have also been linked to jaw osteonecrosis even in patients who have never taken antiresorptives, with an average of about 13 months of exposure before the condition develops.10PubMed. Osteonecrosis of the jaws associated with protein kinase inhibitors: a systematic review
Dental Procedures and Other Triggers
Tooth extractions are the single most common trigger. The extraction creates a wound in the jawbone, and in someone whose bone cannot remodel and heal properly due to medication effects, that wound becomes the entry point for the disease.11Bone. Risk of medication-related osteonecrosis of the jaw after dental extractions in patients receiving antiresorptive agents — A retrospective study of 240 patients This is why dentists and oncologists now emphasize completing any needed dental work before starting these medications whenever possible.
Other local triggers include dental implant placement, ill-fitting dentures that create chronic pressure sores on the gum ridge, periodontal surgery, and even bony growths in the mouth called tori that thin the overlying tissue. Spontaneous cases do occur without any identifiable trigger, but they are less common.
Beyond local triggers, certain systemic conditions raise the stakes. Diabetes is one of the most consistently identified risk factors. It contributes through multiple pathways, including reduced blood flow through small vessels, impaired immune function, and increased inflammation, all of which compromise the jaw’s ability to maintain healthy bone.12PubMed Central. Diabetes as a risk factor for medication-related osteonecrosis of the jaw In prostate cancer patients on bone-targeted drugs, diabetes was associated with roughly five times the risk of developing more severe stages of the disease.13PubMed Central. Cumulative incidence and risk factors for medication-related osteonecrosis of the jaw during long-term prostate cancer management Oral corticosteroid use has also been flagged as a significant risk factor in patients with chronic kidney disease.14Journal of Bone and Mineral Research. Risk factors for osteonecrosis of the jaw in patients with chronic kidney disease: a nested case-control study
What Imaging Reveals That Photos Cannot
Clinical photographs show the surface, but the real extent of damage lies beneath the gums. This is where dental imaging becomes critical, both for diagnosis and for surgical planning. Standard panoramic X-rays can pick up the most common signs: areas of abnormally dense bone (osteosclerosis), areas where bone has been destroyed (osteolysis), and erosion of the outer layer of bone. Cone-beam CT scanning, a three-dimensional imaging technique commonly available in dental offices, goes further. It is better at detecting new bone forming along the outer surface of the jaw (periosteal reaction) and at showing the full extent of cortical bone erosion.15PubMed Central. Qualitative radiographic characteristics of MRONJ-affected bone in oral and parenteral drug administration: comparison of panoramic radiography and cone-beam CT
This matters because what you see clinically in the mouth often underestimates how much bone is affected. A small patch of exposed bone on the surface might correspond to a much larger area of dead bone visible only on a CT scan. Surgeons rely heavily on this imaging to determine how much bone needs to be removed when operating.
Conditions That Look Similar
Several other jaw conditions can look strikingly similar to medication-related osteonecrosis, and misidentification delays appropriate treatment. The two most commonly confused entities are osteoradionecrosis (bone death caused by radiation therapy to the head and neck) and osteomyelitis (a bone infection unrelated to these medications).
Osteoradionecrosis tends to produce more pathological fractures and more skin fistulas than medication-related osteonecrosis. Pain is also more prominent in osteoradionecrosis, and the condition is more likely to require surgical resection rather than conservative management.16International Journal of Oral and Maxillofacial Surgery. Osteoradionecrosis and medication-related osteonecrosis of the jaw: similarities and differences On imaging, periosteal reaction on CT scans appears only in medication-related cases, which can help distinguish the two.17PubMed. Differences between osteoradionecrosis and medication-related osteonecrosis of the jaw Tooth extraction is more commonly the trigger event in the medication-related form.
Jaw metastases from cancer spreading to the bone can also mimic osteonecrosis, producing similar bone destruction and loose teeth. A study comparing cone-beam CT findings across these conditions found that extensive bone-dissolving changes were the dominant feature in osteoradionecrosis, appearing in all scans, while the pattern of findings differed across medication-related osteonecrosis, osteomyelitis, and metastatic disease in ways that experienced radiologists can use to narrow the diagnosis.
Prevention Makes a Dramatic Difference
The most striking finding in the ONJ literature is how powerfully preventive dental care works. One prospective study of cancer patients starting intravenous bisphosphonates implemented a strict three-step dental prevention program. Among those who completed the program, zero cases of osteonecrosis developed, compared to an 8.6% rate in a previous group who received no dental prevention, a statistically significant reduction.18PubMed. Prospective, mono-institutional study of the impact of a systematic prevention program on incidence and outcome of osteonecrosis of the jaw in patients treated with bisphosphonates for bone metastases Other studies have confirmed the pattern: implementing preventive dental programs before and during bone-targeted drug therapy substantially lowers the risk.19Annals of Oncology. Impact of dental care in the prevention of bisphosphonate-associated osteonecrosis of the jaw: a single-center clinical experience
Patients who did not receive comprehensive dental care before starting these medications had roughly nine times the odds of developing osteonecrosis compared to those who did.20PubMed Central. Potential role of comprehensive dental care in preventing medication related osteonecrosis of the jaw (MRONJ): a single centre study The prevention strategy is straightforward: before starting any antiresorptive or antiangiogenic medication, get a thorough dental exam. Have any needed extractions, implants, or periodontal treatments done first and allow time for healing. Once on the medication, maintain regular dental check-ups and report any of the early warning signs immediately.
Treatment When It Does Develop
Treatment depends on severity. For early-stage disease, clinicians often start with conservative management using antibiotics and antiseptic mouth rinses. One retrospective study found that this approach improved signs and symptoms in patients who were not candidates for surgery, making it a reasonable holding strategy for people who are too unwell or unwilling to undergo an operation.21PubMed Central. Conservative non-surgical management in medication related osteonecrosis of the jaw: A retrospective study However, conservative management alone rarely leads to complete healing. A long-term study found that non-surgical protocols for early-stage disease healed the bone in only rare cases, and that the risk of silent disease progression and larger bone loss made early surgical intervention the better path when the patient’s health allows it.22Journal of Cranio-Maxillofacial Surgery. Is the conservative non-surgical management of medication-related osteonecrosis of the jaw an appropriate treatment option for early stages? A long-term single-center cohort study
When surgery is performed, the goal is to remove all dead bone while preserving as much healthy tissue as possible. The results are generally encouraging. A prospective study of cancer patients who underwent surgical resection for ONJ found recurrence rates of about 3% at three months and around 9% at six months, with few complications, and the procedures were not associated with increased long-term mortality.23Oral Oncology. Long-term outcomes of surgical resection of the jaws in cancer patients with bisphosphonate-related osteonecrosis A study of advanced-stage patients using a combined surgical approach achieved complete mucosal healing in all patients by three months after the operation.24Brazilian Journal of Otorhinolaryngology. Combined approach to treatment of advanced stages of medication-related osteonecrosis of the jaw patients
Factors associated with worse surgical outcomes include having a malignant tumor as the underlying condition, certain patterns on imaging such as mixed-type bone hardening and irregular periosteal reactions, and residual abnormalities on post-operative scans.25PubMed Central. Bone resection methods in medication-related osteonecrosis of the jaw in the mandible: An investigation of 206 patients undergoing surgical treatment
Hyperbaric oxygen therapy has been explored as an add-on treatment. The rationale is that flooding the tissues with oxygen can promote healing and influence the cellular signals involved in bone repair. Case reports have described successful outcomes, and early results from controlled trials have been described as encouraging, though the evidence is still limited and this remains an adjunctive therapy rather than a standalone treatment.26PubMed Central. Management of Medication-Related Osteonecrosis of the Jaws With Hyperbaric Oxygen Therapy: A Case Report27PubMed. Utility of hyperbaric oxygen in treatment of bisphosphonate-related osteonecrosis of the jaws
Can a Blood Test Predict Your Risk
You may come across references to a blood test called CTX (C-terminal telopeptide), which measures a marker of bone turnover. The idea is appealing: a simple blood draw could tell your dentist whether it is safe to extract a tooth. A recent meta-analysis found that in patients taking oral bisphosphonates for osteoporosis, a CTX level above 260 pg/mL was associated with an extremely low risk of developing ONJ after oral surgery.28PLOS ONE. Identifying a predictive level of serum C-terminal telopeptide associated with a low risk of medication-related osteonecrosis of the jaw secondary to oral surgery: A systematic review and meta-analysis
The catch is that CTX levels are unreliable for cancer patients on higher-dose antiresorptives, precisely the group at highest risk. And even in osteoporosis patients, individual studies have questioned the test’s accuracy. One study found that using a commonly cited CTX cutoff of 150 pg/mL had a sensitivity of only about 38% and a specificity of 58% for predicting complications, meaning it missed most cases and flagged many patients unnecessarily.29PubMed Central. Value of pre-operative CTX serum levels in the prediction of medication-related osteonecrosis of the jaw (MRONJ): a retrospective clinical study The test may offer some reassurance when levels are high, but a low CTX level does not reliably predict who will develop ONJ. Most specialists use it as one data point in a larger clinical picture rather than as a pass-or-fail gate for dental procedures.
The Psychological Weight of Living With ONJ
Something that clinical photographs and staging systems do not capture is how profoundly this condition affects daily life. A study measuring quality of life in cancer patients with ONJ found that the psychological impact was the most severely affected dimension, with results described as “alarmingly significant.”30PubMed Central. The impact of medication-related osteonecrosis of the jaws on the quality of life in cancer patients Patients deal with chronic pain, difficulty eating, self-consciousness about their appearance, anxiety about the progression of the disease, and frustration that a medication meant to protect their bones has created a new and debilitating problem. Functional limitations, perhaps surprisingly, were the least affected dimension in that study, suggesting that the emotional burden outweighs the physical one for many patients.
This psychological toll underscores why early detection matters so much. Catching warning signs at the soft-tissue stage, when gums are swollen or a socket is not healing, gives clinicians far more options than waiting until bone is exposed and infection has set in. If you are on any of the medications discussed here, consider keeping a phone camera handy for your mouth. Photographing any area that concerns you provides a visual record you can share with your dentist and track changes over time. The pictures in medical journals can seem abstract until the problem is your own mouth, and by then you want to have caught it early.