Clinical findings, epidemiology, etiology, and pathophysiology
- Area of exposed bone that does not heal
- Numbness or paresthesias within the mouth or jaw
- Pain
- Swelling
- Non-healing sore or ulcer in the mouth
- Incidence of osteoradionecrosis estimated at around 2%
- Improvement in radiation therapy has decreased the incidence
- Radiation therapy causes DNA damage and cell death
- Tumor cells are more susceptible to radiation damage
- Excessive radiation doses can cause normal cells to be overwhelmed by DNA damage
- ORN is the result of cumulative tissue damage caused by radiation
- Radiation creates disturbances in cell metabolism and homeostasis
- Hypovascular environment due to injury to endothelial cells
- Decreased oxygen delivery leads to hypoxic tissues
- ORN is essentially hypocellular-hypovascular-hypoxic tissues

Risk factors, prevention, and treatment
- Size and location of tumor
- Dose and delivery of radiation
- Smoking
- Diabetes mellitus
- Presence of dental disease
- Prevention strategies aim to avoid excess doses of radiation
- Maintaining excellent dental hygiene can help prevent ORN
- Treatments vary depending on disease severity
- Medical treatment with antibiotics
- Hyperbaric oxygen therapy (HBO) or surgical debridement/reconstruction can be used as treatments

Staging and prevention
- Staging system provides baseline reference for management after diagnosis
- No universally accepted prevention and management
- Many proposed preventive approaches lack high quality evidence
- Lack of evidence to determine most effective approach
- Uncertainty for clinicians and patients in choosing treatment
- Dental assessment recommended before radiotherapy
- Strict preventive regime paired with IMRT can prevent ORN
- Dental extractions are a major risk factor but not recommended as treatment
- Frequency of ORN similar in pre- and post-radiotherapy extractions
- Teeth extraction should consider prognosis, oral care, and patient's wishes
- Tooth brushing technique and habit should be high standard
- Chlorhexidine mouthwash and fluoride regime encouraged
- Tailored oral care for trismus and altered taste
- High level of motivation and regular dental appointments important
- Denture adjustments to avoid ORN secondary to trauma

Management options
- Antiseptic mouthwashes and analgesics for acute ORN
- Tetracyclines and penicillin antibiotics to eliminate infection
- Ultrasound therapy improves blood circulation and induces healing
- Hyperbaric oxygen therapy (HBO) recommended by some studies
- Conservative approaches to manage ORN
- Hyperbaric Oxygen Therapy (HBO)
- First described in 1973 as an adjunctive treatment for ORN
- Increases tissue oxygen tension
- Improves collagen synthesis, angiogenesis, and epithelialization
- Controversial use as the only method for ORN management
- Little evidence of clinical benefit and questionable therapeutical significance
- Surgical Management
- Multidisciplinary approach combining HBO therapy and surgery
- Improves local blood circulation
- Resection of necrotic bone and reconstruction with a free flap
- Some studies question the benefit of HBO therapy
- Microvascular reconstruction without HBO therapy is successful
- Pharmacological Methods
- Pentoxifylline enhances blood flow and reduces cytokine cascade
- Tocopherols (vitamin E) inhibit platelet aggregation and scavenge reactive oxygen species
- Clodronate inhibits bone resorption and increases bone formation
- Pharmacological methods target etiologic factors of ORN
- Pentoxifylline not meant for long-term treatment of ORN
- Surgical Procedures
- Removal of small sequestra
- Sequestrectomy
- Alveolectomy with primary closure
- Closure of orocutaneous fistula
- Large resections for advanced disease or failed conservative measures

References (not included in the content grouping)