Treatment of Osteoradionecrosis (ORN)
Treatment of ORN must be stratified by disease severity: partial thickness ORN (ClinRad stage I-II) should begin with medical management and minor transoral debridement, while full thickness ORN (ClinRad stage II-III) requires segmental resection with free flap reconstruction. 1
Medical Management
First-Line Pharmacological Therapy
Pentoxifylline 400 mg twice daily combined with tocopherol 1,000 IU once daily, plus antibiotics and prednisolone is the cornerstone of medical management for mild, moderate, and severe ORN in cancer-free patients. 1 This combination (PENTOCLO protocol) demonstrates superior healing rates compared to pentoxifylline alone. 1, 2
Broad-spectrum antibiotics should be administered when signs of infection are present, with amoxicillin 500 mg TID for 7-10 days or levofloxacin for penicillin-allergic patients. 3, 4
Antiseptic mouth rinses with chlorhexidine gluconate (0.12% or 0.2%) or povidone-iodine should be performed at least twice daily until sufficient healing is achieved. 1, 3
Hyperbaric Oxygen Therapy
HBO therapy in conjunction with surgical intervention may be used in cancer-free patients with mild, moderate, and severe ORN, with potential benefit most likely observed in mild cases. 1 However, the evidence remains limited and inconclusive regarding its effect across different severity grades. 1
Routine prophylactic HBO is not recommended prior to dental extractions in previously irradiated patients. 1
Surgical Management Algorithm
Partial Thickness ORN (ClinRad Stage I-II)
Partial thickness ORN is defined as disease where removal of all necrotic bone leaves sufficient structural integrity such that oroantral/oronasal defect is unlikely in the maxilla and pathological fracture is unlikely in the mandible. 1
Begin with transoral minor intervention including debridement, sequestrectomy, alveolectomy, and soft tissue flap closure. 1 This approach can lead to resolution in many cases. 1
Small defects <2.5 cm in length may heal spontaneously with local measures. 1
Larger defects must be covered with vascularized tissue. 1
Full Thickness ORN (Selected ClinRad Stage II and All Stage III)
Full thickness ORN is defined as disease where removal of all necrotic bone will likely result in oroantral/oronasal defect in the maxilla or pathological fracture in the mandible. 1
Segmental maxillectomy or mandibulectomy with free flap reconstruction is the definitive treatment. 1 This applies to all full thickness ORN and extensive partial thickness ORN where conservative therapy has failed. 1
Osteomyocutaneous free flap reconstructions are recommended for mandibular continuity defects. 1 Free flaps demonstrate 92% success rates with only 4% total flap loss. 5, 4
For maxillectomy defects extending into the sinus, reconstruction can be performed with myocutaneous or osteomyocutaneous flaps, with the latter allowing dental implantation. 1
Free flaps are superior to pedicle flaps due to greater versatility and improved outcomes. 1 Pedicle flaps may be used in salvage procedures or when patient medical status is compromised. 1
Critical Decision Points
Determining Surgical Extent
Preoperative radiographic interpretation of compromised bone extent, with intraoperative confirmation via bleeding bone endpoint, should guide resection margins. 1
The surgical endpoint is reaching viable, bleeding bone that indicates adequate vascular supply. 1, 6, 7
When Conservative Management Fails
If conservative therapy does not yield appropriate disease control in partial thickness ORN, escalate to segmental resection. 1 Persistent ORN despite diligent treatment raises suspicion for recurrent cancer. 7
Extensive ORN with multiple discharging fistulae, large areas of exposed necrotic bone, or coexistent fracture should be treated primarily with radical sequestrectomy and microvascular free flap reconstruction. 7
Common Pitfalls and Caveats
Bacterial biofilm formation in necrotic areas may interfere with systemic antibiotic efficacy, requiring higher doses or longer treatment courses. 3 Antibiotics alone are insufficient for advanced ORN. 3
Underestimating the extent of necrosis and attempting conservative management for full thickness disease leads to treatment failure. 4 The distinction between partial and full thickness must be made accurately. 1
Inadequate resection margins result in persistent disease. 4 Intraoperative frozen section assessment should confirm complete removal of necrotic tissue. 5
Routine antibiotic therapy is not recommended unless clinically indicated by signs of infection. 3
For patients with prior radiation doses ≥50 Gy to the mandible or maxilla, pentoxifylline/tocopherol therapy should be maintained throughout the healing period. 5