Jaw Osteonecrosis


Jaw Osteonecrosis, Jaw Aseptic Necrosis, Mandibular Osteonecrosis, Mandible Aseptic Necrosis, Bisphosphonate-Associated Osteonecrosis of the Jaw

  • Pathophysiology
  1. Mandibular alveolar process undergoes constant bone remodeling
    1. Osteoclast-mediated bone resorption
    2. Osteoblast-mediated bone deposition
  2. Medications may disrupt bone remodeling
    1. Osteoclast apoptosis or inhibition
    2. Decreased localized Blood Flow
  3. Mandible is at increased risk of osteonecrosis due to increased bone turnover rate
  • Risk Factors
  1. Tooth Extraction
    1. Precedes drug-induced Jaw Osteonecrosis in 45-61% of cases
  • Causes
  1. Intravenous Bisphosphonates (occurs in 3-18% of patients)
    1. Zoledronic acid (Reclast)
    2. Ibandronate (Bonival)
  2. Oral Bisphosphonates (occurs in 0.1 to 0.2% of patients)
    1. Alendronate (Fosamax)
    2. Risedronate (Actonel)
  3. Other agents
    1. Denosumab (Prolia) - occurs in 0.7 to 1.9% of patients
    2. Antiangiogenic Medications
      1. Chemotherapeutic agents that block solid tumor Angiogenesis
  • Signs
  1. Exposed, necrotic bone
  2. Tooth socket remains after Tooth Extraction
  3. Suppurative discharge from osteonecrosis site
  4. Mucosal sloughing
  5. Persistent jaw pain
  6. Fistula formation
  7. Gingival Hypertrophy or bone hypertrophy
  • Imaging
  1. Mandible XRay demonstrates radiolucency of bone in necrotic areas
  • Prevention
  1. Avoid dental surgery if patient is on intravenous Bisphosphonates, Antiangiogenic Medications, Denosumab
  2. Exercise caution in performing dental surgery on those on oral Bisphosphonates for >4 years
    1. Dentists typically will ask for medical clearance for dental surgery in these cases
  3. Oral bisphosphonate holiday (not evidence based, but standard of care in dental practice as of 2020)
    1. Stop oral Bisphosphonates for 2 months before dental procedure
    2. Wait at least 3 months after dental procedure to restart oral Bisphosphonates