A non-healing mandibular socket in a woman receiving denosumab
A 71-year-old woman is referred by her general dentist because a socket in the right posterior mandible has not healed. Tooth 46 was extracted 10 weeks ago because of a periapical infection; the extraction was described as difficult, and the socket broke down a few weeks later. Her medical history includes osteoporosis, for which she has received denosumab 60 mg subcutaneously every 6 months for 3 years, the most recent injection 4 months ago. She also takes calcium and vitamin D, and perindopril for hypertension. She is a non-smoker, has never had radiotherapy to the head and neck, and her recent HbA1c is normal. She feels well and has no fever. On examination there is a 1 cm area of exposed, yellow-white necrotic bone at the 46 site, with mild tenderness but no erythema, no pus, no fistula and no swelling. Mouth opening is normal. A CBCT shows a small sequestrum with surrounding sclerosis but no fracture and no extension beyond the alveolar bone.
1. Give your diagnosis and stage it, explaining why it is not the next stage up.
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Diagnosis: medication-related osteonecrosis of the jaw, Stage 1.
The diagnosis requires three elements, all present: current or previous antiresorptive treatment - denosumab for three years; exposed bone or bone probed through a fistula persisting for more than eight weeks - here 10 weeks; and no history of head and neck radiotherapy or of obvious metastatic disease in the jaw.
Why Stage 1 and not Stage 2: Stage 2 requires evidence of infection - purulence, erythema, fistula, or pain with swelling. This patient has exposed necrotic bone with mild tenderness only; there is no discharge, no erythema, no fistula and no swelling. Mild pain alone does not move the case into Stage 2. It is also not Stage 0, because Stage 0 describes non-specific symptoms or radiographic change without exposed bone. It is not Stage 3, because there is no extension beyond the alveolar bone, no pathological fracture, no extraoral fistula and no sinus involvement.
Why not simple osteomyelitis or a retained root: chronic osteomyelitis usually shows a more diffuse mixed radiolucency with periosteal reaction and often a sinus tract, and there is a clear antiresorptive exposure with a time course consistent with MRONJ. A retained root would appear as a distinct radiopaque structure rather than a sequestrum with sclerosis. If any doubt remains, the history of denosumab is the decisive factor; assuming it is ordinary osteomyelitis and curetting the bone can convert a Stage 1 lesion into a much larger defect.
2. Outline your management at this visit, including what you would deliberately avoid.
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Conservative management, because she is Stage 1.
- Local measures. Chlorhexidine 0.12% mouthwash twice daily, gentle saline rinses, and meticulous oral hygiene with a soft brush around the site. Advise avoiding trauma from food or a denture base over the area.
- Analgesia with paracetamol. Use NSAIDs cautiously given perindopril and age-related renal risk.
- No antibiotics at this stage, because there is no clinical infection; antibiotics without infection add resistance pressure and do not heal exposed bone.
- No surgical debridement and no sequestrectomy now. In Stage 1, aggressive debridement risks extending the necrotic field. A small mobile sequestrum may be allowed to separate spontaneously, but that is a later decision.
- Review monthly with measurement and photographs of the exposed area, and repeat imaging only if the clinical picture changes. Many Stage 1 lesions remain stable or heal over months.
- Coordinate with her physician and inform the dentist who referred her.
Escalation criteria: if erythema, purulence, a fistula or increasing pain and swelling develop - that is, progression to Stage 2 - add a systemic antibiotic, typically amoxicillin with metronidazole, or clindamycin if allergic, together with superficial debridement. Stage 3 disease, with fracture, extraoral fistula or extension to the inferior border, requires specialist resection.
Avoid over-treatment. Doing too much too early is the commonest error in Stage 1 disease.
3. She asks whether she should stop denosumab so that the bone will heal, and whether future extractions are now forbidden. How do you answer?
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On stopping denosumab: she must not stop it on dental advice alone. Denosumab is a RANKL inhibitor with a half-life of about a month; its effect wanes within months of the last dose, and discontinuation is associated with rebound bone loss and an increased risk of vertebral fracture. Unlike bisphosphonates, it is not retained in the skeleton in the same way, so a conventional drug holiday offers little benefit and carries a real systemic cost. There is no evidence that interrupting denosumab improves MRONJ healing, and CTX testing has not been validated for denosumab. Any decision must be made jointly with the prescribing physician, who will weigh fracture risk.
On future extractions: they are not forbidden, but they must be planned. The risk in osteoporosis dosing is low - generally quoted well under 1% in this population - which is materially different from the oncology doses used for myeloma or bone metastases. For any future extraction: discuss the risk and obtain documented informed consent; use an atraumatic technique with elevation rather than excessive force; remove sharp bone edges; aim for primary closure; use preoperative chlorhexidine; consider postoperative antibiotics if healing is likely to be impaired; and review at one and four weeks.
Also discuss: avoid elective surgical procedures in the region where possible, keep the remaining teeth periodontally healthy to reduce future extractions, ensure dentures are well fitting and relieved over the site, and report any non-healing sore immediately. Emphasise that the dental team and her physician will communicate, so that she is not left to decide between conflicting instructions.