Exposed necrotic bone in a patient on zoledronic acid

§Chief complaint

Rough painful area of exposed bone in the lower jaw for 4 months

§Medical & dental history

• 01Metastatic breast carcinoma on IV zoledronic acid for 3 years
• 02Previous corticosteroid therapy
• 03No head and neck radiotherapy
• 04Extraction of 36 five months ago without preventive assessment

§Clinical examination

• 01Exposed necrotic bone 15 mm at the 36 site, non-healing
• 02Surrounding mucosal inflammation with purulent discharge
• 03Tenderness and halitosis; no extraoral sinus
• 04No paraesthesia

§Figures

§Differential diagnosis

§Final diagnosis

Medication-related osteonecrosis of the jaw, AAOMS stage 2, mandible

Three criteria define MRONJ: current or previous antiresorptive/antiangiogenic therapy, exposed bone or a fistula persisting more than 8 weeks, and no history of radiation to the jaws. Stage 2 adds infection with pain.

§Investigations

• 01OPG and CBCT — osteolysis with sequestrum and persisting extraction socket outline
• 02Biopsy only if metastasis is suspected, with the caveat that biopsy can extend necrosis
• 03FBC, CRP; oncology liaison regarding drug holiday

§Treatment plan

• 01Conservative first: chlorhexidine 0.12 percent rinses, culture-directed antibiotics, analgesia
• 02Removal of loose sequestra and sharp bony edges only
• 03Surgical resection with primary closure for refractory or stage 3 disease
• 04Preventive dental care before any future antiresorptive therapy

§Surgical procedure

• 01Limited sequestrectomy and marginal debridement to bleeding bone
• 02Tension-free primary mucosal closure
• 03Perioperative antibiotics for 2 weeks

§Histopathology report

Necrotic bone with bacterial colonies (including Actinomyces) and no viable osteocytes; surrounding chronic inflammation. No evidence of metastatic carcinoma.

§Follow-up & outcome

• 01Mucosal coverage achieved at 10 weeks
• 02Pain-free at 6 months, no re-exposure
• 03Dental prevention protocol before resuming antiresorptive therapy

§Clinical pearls / learning points

• 01Prevention is everything: dental clearance and healing before starting antiresorptives.
• 02A drug holiday is an oncology decision, and the evidence for benefit is weak.
• 03Exclude jaw metastasis in a cancer patient — MRONJ and metastasis can coexist.

§References

• Ruggiero SL et al. AAOMS Position Paper on MRONJ, 2022 update.

§Related diseases

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