II. Pathophysiology
- Mandibular alveolar process undergoes constant bone remodeling
- Osteoclast-mediated bone resorption
- Osteoblast-mediated bone deposition
- Medications may disrupt bone remodeling
- Osteoclast apoptosis or inhibition
- Decreased localized Blood Flow
- Mandible is at increased risk of osteonecrosis due to increased bone turnover rate
III. Risk Factors
- High dose or long duration of triggering medication
- Corticosteroid use (in combination with other causative agents below)
-
Tooth Extraction (or dental implant)
- Precedes drug-induced Jaw Osteonecrosis in 45-61% of cases
- Dentures and gum inflammation may also increase risk
- Head and Neck Radiation Therapy
- Increased risk at sites exposed to >60 Gy radiation
- Nabil (2011) Int J Oral Maxillofac Surg 40(3): 229-43 [PubMed]
IV. Causes: Osteoporosis Agents
- Intravenous Bisphosphonates (occurs in 3-18% of patients)
- Zoledronic acid (Reclast)
- Ibandronate (Bonival)
- Oral Bisphosphonates (occurs in 0.1 to 0.2% of patients)
-
Denosumab (Prolia)
- RANK Ligand Inhibitor used in Osteoporosis, bone matastases, giant cell Bone Tumors
- Occurs in 0.7 to 1.9% of patients
- Romosozumab (Eventity)
- Sclerostin inhibitor used in Osteoporosis
V. Causes: Chemotherapeutic Agents
- Antiangiogenic Medications (monoclonal antibodies or Nucleic Acids)
- Chemotherapeutic agents that block solid tumor Angiogenesis (Vascular Endothelial Growth Factor)
- Bevacizumab (Avastin)
- Ramucirumab
- Ranibizumab
- Pegaptanib
- Tyrosine Kinase Inhibitors
- References
VI. Signs
- Exposed, necrotic bone
- Tooth socket remains after Tooth Extraction
- Suppurative discharge from osteonecrosis site
- Mucosal sloughing
- Persistent jaw pain
- Fistula formation
- Gingival Hypertrophy or bone hypertrophy
VII. Imaging
- Mandible XRay demonstrates radiolucency of bone in necrotic areas
VIII. Prevention
- Alert dentist to Radiation Therapy to head and neck
- Perioperative hyperbaric oxygen may be indicated prior to procedure
- Avoid dental surgery if patient is on intravenous Bisphosphonates, Antiangiogenic Medications, Denosumab
-
Exercise caution in performing dental surgery on those on oral Bisphosphonates for >4 years
- Dentists typically will ask for medical clearance for dental surgery in these cases
- Oral bisphosphonate holiday
- Not evidence based (however standard of care in dental practice as of 2020)
- Stopping bisphosponates has NOT been shown to modify risk
- Protocol
- Stop oral Bisphosphonates for 2 months before dental procedure
- Wait at least 3 months after dental procedure to restart oral Bisphosphonates
- Not evidence based (however standard of care in dental practice as of 2020)
IX. References
- (2023) Presc Lett 30(6): 33
- Glick (2020) Am Fam Physician 102(10):613-21 [PubMed]