Medication Related Osteonecrosis of the Jaw

Question 1

What is MRONJ?

Answer 1

History of previous or current treatment with anti-resorptive or anti-angiogenic medication.
Leads to exposed bone / sinus tract in the maxillofacial region that has persisted for more than 8 weeks.
No current radiation to the jaw.

Question 2

Who takes anti-resorptive or anti-angiogenic drugs?

Answer 2

• Osteoporosis (Anti-resorptive)
• Hypercalcemia (Anti-resorptive)
• Bone diseases e.g. pagets, osteogenesis imperfecta, fibrous dysplasia
• Metastatic bone cancer e.g. breast, prostate, lung

Question 3

How does anti-resorptive and anti-angiogenic drugs work?

Answer 3

Anti-resorptive: Depress osteoclasts and diminish resorption of bone

Anti-angiogenic: stop tumours growing their blood vessels to decrease tumour size

Question 4

Name some anti-resoptive drugs?

Answer 4

Alendronic acid, ibandronic acid, pamidronic acid, risedronic acid, zoledronic acid, denosumab

All work by osteoclast inhibition

Question 5

Name some anti-angiogenic drugs

Answer 5

Axitinib, bevacizumab, cabozantinib, vandetanib

Question 6

How does denosumab work?

Answer 6

Anti-resorptive. Inhibits osteoclast function and associated bone resorption. Works by inhibiting the RANK ligand.

Question 7

What is the criteria for the MRONJ?

Answer 7

• History of bisphosphonates / antiangiogenic therapy
• No history of radiotherapy
• No evidence of healing for more than 8 weeks with appropriate care

Question 8

What are the 4 stages of MRONJ?

Answer 8

• Stage 0: no clinical evidence of necrotic bone BUT non-specific clinical findings, radiographic changes
• Stage 1: Exposed and necrotic bone, or fistulae that probes to bone, in patients who are asymptomatic and have no evidence of infection
• Stage 2: Exposed and necrotic, or fistulae that probes to bone, associated with infection as evidenced by pain and erythema in the region of exposed bone +- pus
• Stage 3: Exposed or necrotic bone or a fistula that probes in patients with pain, infection and either pathogenic fracture, extra-oral fistula, oral antral/oral nasal communication

Question 9

What are the risk factors for MRONJ?

Answer 9

• Route: oral or IV, duration, dose, potency
• Complex MH: diabetes, HIV
• Medications: chemotherapy, steroids
• Oral health
• Type of dental treatment

Question 10

What dental prophylactic treatment for Antiangiogenic / resorptive drugs?

Answer 10

Ideally all patient should have a pre-dental assessment.
- Extraction of all poor prognosis
- Allow for mucosal healing prior to starting
- Encourage good OH

Question 11

How do we manage patients already on anti-angiogenic or resorptive drugs?

Answer 11

• Regular dental check ups
• Maintain OH
• Non-oral surgery related treatment can be done in primary care
• Restorations
• Endodontics preferred
• Non-surgical periodontal treatment