Exposed bone on denosumab: staging, conservative care and the drug holiday question
A 74-year-old woman is referred by her GDP with a 1 cm area of exposed bone on the lingual aspect of the lower left first molar region (36), present for 10 weeks. She had a difficult extraction of 36 four months ago. She has breast cancer with bone metastases and has received denosumab 120 mg subcutaneously monthly for 20 months, alongside letrozole. She is edentulous in the upper arch and has teeth from 34 to 45. She has no pain and no pus; there is slight erythema at the mucosal margins, and the adjacent 37 has a large amalgam restoration with no caries. Mouth opening is 40 mm, there is no paraesthesia and no cervical lymphadenopathy. She is a non-smoker with well-controlled hypertension. She asks whether stopping the bone injection would let the hole heal, and whether 37 should be extracted before it causes trouble.
1. What is your diagnosis and how would you confirm it? What else must be excluded?
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Diagnosis: medication-related osteonecrosis of the jaw (MRONJ). She meets the case definition - exposed bone, or bone probed through a fistula in the maxillofacial region, persisting for more than 8 weeks in a patient taking an antiresorptive agent, with no history of radiotherapy to the jaws and no obvious jaw metastasis.
Staging (AAOMS): exposed bone with no pain, no suppuration and no infection is Stage 1; the marginal erythema does not upgrade it. Stage 0 is no exposed bone but non-specific symptoms; Stage 2 is exposed bone with infection; Stage 3 is extensive disease (beyond the alveolar process, pathological fracture, extraoral fistula, sinus involvement).
Confirm and exclude:
- Probe and vitality-test 37 and adjacent teeth; take a periapical radiograph and, if needed, a CBCT to look for sequestrum, pathological fracture or periapical pathology.
- Exclude recurrent or metastatic malignancy in the mandible - a lytic lesion, rapid growth, paraesthesia or unexplained tooth mobility would raise suspicion and warrant urgent oncology review and imaging.
- Exclude osteoradionecrosis (no radiotherapy here), chronic osteomyelitis, and traumatic ulceration from a sharp tooth or appliance.
2. Outline your management of the exposed bone, including what you would avoid.
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Stage 1 is managed conservatively. The aim is to prevent progression to Stage 2 or 3, not to achieve rapid mucosal closure.
- Oral hygiene: chlorhexidine 0.12% mouthwash twice daily, saline rinses, gentle brushing, and professional cleaning of adjacent teeth while avoiding the exposed area.
- Remove trauma: smooth sharp bone or tooth edges and relieve any appliance pressure.
- Analgesia only if required; antibiotics are not indicated at Stage 1 without infection.
- Review every 3 months with measurement and photographs; many Stage 1 lesions remain stable for years and some mucosalise slowly.
- Optimise general health: nutrition, glycaemic control, smoking status.
What to avoid:
- Aggressive surgical debridement, sequestrectomy or resection at Stage 1 - surgery in an antiresorptive patient can extend the zone of necrosis.
- Elective extractions, including 37, and periapical surgery or implant placement in the region.
- Routine bone biopsy to confirm the diagnosis when the clinical picture is typical.
If she progresses to Stage 2 (suppuration, pain, swelling), add oral antibiotics (for example amoxicillin with metronidazole, or clindamycin if penicillin-allergic) alongside the measures above. Stage 3 needs surgical management in a specialist unit.
3. How would you answer her two questions?
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On stopping denosumab: explain that this is not a decision either of you can take alone, and that the evidence that a drug holiday helps established MRONJ heal is weak. Denosumab is given to reduce skeletal-related events - pain, pathological fracture, spinal cord compression and hypercalcaemia - and stopping it carries a real risk of these. Unlike bisphosphonates, its effect on bone turnover reverses within roughly 6–9 months of the last dose, so any theoretical benefit is short-lived; in metastatic disease the oncologist will usually want to continue. The decision should be made jointly with her oncologist, with the risks of skeletal events and of MRONJ progression both on the table. Do not advise her to stop it yourself.
On extracting 37: advise against it. An elective extraction in a patient on monthly high-dose denosumab carries a meaningful risk of precipitating a new site of MRONJ, and a heavily restored but asymptomatic tooth is not an indication. If 37 later becomes unrestorable or infected, discuss options with the oncology team: root canal treatment is preferable to extraction; if extraction becomes unavoidable, do it atraumatically with antibiotic cover, primary closure and chlorhexidine, and document the discussion.