Osteonecrosis of the Jaw (ORN, MRONJ, BRONJ)

There are two main forms, both relevant to cancer survivors:

Osteoradionecrosis (ORN): caused by reduced blood flow following head and neck radiation. Can develop spontaneously or following an extraction or trauma, sometimes years after radiation completed.

Medication-related osteonecrosis of the jaw (MRONJ): caused by certain medications, most commonly bisphosphonates (Zometa, Reclast, Aredia, Bonefos) and denosumab (Xgeva, Prolia). When specifically caused by bisphosphonates, sometimes called BRONJ.

Both can be serious, both are manageable in most cases with appropriate care, and both benefit from clinicians who treat them regularly.

Symptoms and Presentation

Osteonecrosis can present in several ways:

• Exposed bone in the mouth: the most characteristic sign, often visible at an extraction site, under a denture, or along the gumline
• Persistent pain in the jaw: sometimes the first symptom before bone becomes visible
• Loose teeth that were previously stable
• Drainage or pus from a site in the mouth
• Non-healing extraction sockets: sites that should have closed but have not
• Numbness in the lower lip or chin (in advanced lower jaw cases)
• Visible separation of bone fragments (sequestrum formation)
• Swelling, redness, or fistula in surrounding tissues

Early-stage disease can be subtle, sometimes just a small area of exposed bone with no pain. Advanced disease can involve large segments of jaw with significant functional impact.

Diagnosis

We diagnose osteonecrosis through:

Detailed history. Cancer treatment history, radiation field and dose, current and prior medications (particularly bisphosphonates and denosumab), recent dental procedures, and timing of symptoms.

Clinical exam. Visual and tactile examination of the affected area, evaluation of surrounding tissues, and assessment of overall oral health.

Imaging. Panoramic X-rays, periapical X-rays, and often CBCT (3D cone beam CT) to evaluate the extent of bone involvement.

Staging. Established staging systems for both ORN and MRONJ guide treatment decisions. Stage at diagnosis substantially influences management.

Treatment

Treatment depends on cause, stage, location, and individual factors.

Conservative management is often first-line, particularly for early-stage disease:

• Antimicrobial mouth rinses (typically chlorhexidine)
• Targeted antibiotics when infection is present
• Analgesics for pain control
• Avoidance of mechanical trauma to the affected site
• Removal of small bone sequestra when they have separated naturally
• Frequent monitoring for progression or healing

Many patients stabilize with conservative care, particularly with MRONJ where the medication can sometimes be paused (in coordination with oncology) and with ORN where smaller lesions can resolve over time.

Surgical management is sometimes needed:

• Sequestrectomy (removal of separated bone fragments)
• Debridement of larger areas of dead bone
• Marginal or segmental resection in advanced cases (typically hospital-based, with oral and maxillofacial surgery)

We coordinate with oral surgery for surgical management when needed. Many cases can be handled in our office; advanced cases benefit from hospital-based care.

Hyperbaric oxygen therapy (HBO) is sometimes used as an adjunct, particularly for ORN. Evidence on HBO is mixed; we recommend it for selected cases based on individual circumstances.

Coordination with oncology. For MRONJ patients, we often communicate with the medical oncologist about whether (and how) to modify the bone-modifying drug regimen. Decisions involve weighing dental and oncology priorities.

Prevention

For patients at risk, prevention is more effective than treatment:

Pre-treatment dental clearance. Patients about to begin head and neck radiation, bisphosphonates, denosumab, or anti-angiogenic therapy benefit from a dental evaluation before treatment starts. Hopeless teeth should be addressed before bone-modifying drugs or radiation begin.

Conservative dentistry for at-risk patients. Patients with prior radiation or active bisphosphonate therapy should generally avoid extractions unless necessary. Restorative work, crowns, root canal therapy, often serves better than extraction.

Coordination with the oncology team. For patients on or about to start bone-modifying drugs, dental work should be timed and coordinated.

Education for survivors. Patients should know their risk and tell every dentist about radiation history and bone-modifying drug exposure, even years later. This information is critical and often forgotten.

Working With Your Care Team

Osteonecrosis sits at the boundary of dentistry and medicine, and management often involves:

• Medical oncology, particularly for MRONJ patients on active therapy
• Radiation oncology, for context on prior treatment and risk assessment
• Oral and maxillofacial surgery, for surgical management of advanced cases
• Hyperbaric medicine, when HBO is indicated
• Infectious disease, when secondary infection complicates the picture

We coordinate routinely with these specialists.