What is the estimated relative risk of developing medication-related osteonecrosis of the jaw (MRONJ) in a patient on Prolia (denosumab) for osteoporosis undergoing extraction of a non-restorable mandibular molar?

Risk of MRONJ Following Mandibular Molar Extraction in a Patient on Denosumab for Osteoporosis

The estimated relative risk of developing medication-related osteonecrosis of the jaw (MRONJ) for a 69-year-old woman on Prolia (denosumab) for osteoporosis requiring extraction of a non-restorable mandibular molar is approximately 0.7-1.1% in the first year of treatment, increasing to 3.7% in the second year and 4.6% per year thereafter. 1

Risk Assessment for MRONJ in This Patient

• Denosumab (Prolia) administered at 60mg every 6 months for osteoporosis carries a significantly higher risk of MRONJ compared to bisphosphonates, with a rate ratio of 6.3 (95% CI 2.1 to 22.8) 2
• The patient's three-year duration of denosumab therapy places her at elevated risk, as MRONJ incidence increases with longer treatment duration 1
• Dental extraction is the most significant independent risk factor for developing MRONJ 3
• The mandibular location of the extraction further increases risk, as MRONJ lesions occur more commonly in the mandible than in the maxilla 1

Additional Risk Factors to Consider

• Recent studies indicate that dental infection at the extraction site significantly increases MRONJ risk in osteoporosis patients (OR 22.77; 95% CI 2.85-181.62) 4
• Other risk factors that should be assessed include:
  • Poor oral hygiene 1
  • Ill-fitting dentures 1
  • Uncontrolled diabetes mellitus 1
  • Tobacco use 1
  • Concurrent glucocorticoid therapy 5

Risk Reduction Strategies

• Preventive measures can significantly reduce MRONJ risk:

  • Use of leukocyte and platelet-rich fibrin during extraction can reduce risk by 84% 4
  • Perioperative antibiotic prophylaxis can reduce risk by 86-93% 4
  • Ensuring atraumatic extraction technique and primary wound closure 5

• For high-risk patients like this one, consider:

  • Comprehensive oral evaluation before extraction 1
  • Systematic follow-up every 6-8 weeks until complete mucosal healing occurs 1
  • Communication between the dental specialist and the prescribing physician regarding healing status 1

Important Considerations Regarding Drug Holiday

• There is insufficient evidence to support or refute the need for temporary discontinuation of denosumab before dental extraction 1
• The decision to defer denosumab administration should be made at the discretion of the treating physician in consultation with the patient and oral health provider 1
• For patients with bone metastases (not applicable to this osteoporosis patient), an interval since last administration of at least 3 months has been shown to reduce MRONJ risk (OR 0.83; 95% CI 0.72-0.97) 4

Post-Extraction Monitoring

• The patient should be monitored closely for signs of MRONJ development:

  • Exposed bone or bone that can be probed through an intraoral fistula persisting for more than 8 weeks 1
  • Pain, infection, or inflammation at the extraction site 1
  • Radiographic changes showing osteolysis or decreased trabeculation 1

• Healing should be assessed using objective criteria:

  • Mucosal coverage (complete healing indicates resolution) 1
  • Absence of pain 1
  • Absence of infection/inflammation 1
  • Radiographic evidence of normal trabecular pattern 1

In summary, this patient faces a moderate but significant risk of MRONJ following mandibular molar extraction due to her three-year history of denosumab therapy. Implementation of preventive strategies, careful surgical technique, and vigilant post-extraction monitoring are essential to minimize this risk and ensure optimal outcomes.