Jaw necrosis (osteoradionecrosis)
Osteoradionecrosis is characterized by a non-healing area of exposed bone of at least 6 months duration in a patient who has been treated with radiation therapy. It is not an infection in itself but because of the radiation treatment normal cells are destroyed leading to damaged arteries, reduced circulation and reduced healing ability of the bone. Therefore, any subsequent infections of the jaw can lead to increased risk of osteoradionecrosis.
Occasionally osteoradionecrosis can develop spontaneously in post radiated patients, but it is most commonly seen when irradiated bone sustains an injury because of a tooth extraction, surgery or denture irritation.
- Patients who have received radiation treatment for head and neck cancers.
- Risk increases with higher radiation dosage and among patients who receive both radiation and chemotherapy.
- Although there are no specific clinical signs, numbness or paresthesia of the lip may be an early indicator
- Infected teeth or gums
- Non-healing necrotic bone, which may or may not be exposed
- Extraoral: draining sinuses.
- Initially, completely asymptomatic
- Onset of symptoms may occur months to years after initial radiation treatment
- Pain severity: may range from mild to severe, depending on the extent of involvement.
- Obtain a detailed history:
- Ask about the onset and nature of pain or discomfort.
- Ask about the patient's medications (e.g., bisphosphonates), when the therapy was started and for how long is it was prescribed.
- Ask about any history of radiation therapy.
- Ask about any illnesses or other conditions.
- Perform a complete extraoral and intraoral examination (examine all oral mucosal surfaces): Extraoral exam:
- Complete a thorough head and neck lymph node examination.
- Look for any extraoral draining sinuses or scars.
- Examine any exposed bone surfaces and adjacent dental and periodontal tissues.
- Palpate to examine for continuity of the lower border of the mandible. In cases with a pathological fracture, there may be a step deformity.
- Check for lip numbness and sensation in soft tissues, which would suggest nerve involvement.
- Check for any draining sinuses or scars: in case of draining sinuses, send the pus for microbial culture.
- Prescribe radiographs: panoramic or periapical radiographs to assess the extent of bone destruction. Advanced imaging modalities, such as CT scan or radionuclide scan, may be advised for bone evaluation.
- Radiographic considerations:
- Radiographs may show mixed radiolucent and radiopaque lesions, representing area of bone destruction which may involve alveolar and basal bone with or without encroachment on the mandibular canal.
- Subclinical cortical and lamina dura thickening may also be present.
- Other findings are nonhealing extraction sockets, periapical radiolucencies, osteolysis, sequestra, oroantral fistula, and periosteal new bone formation.
- Pathological mandibular fractures may present as step deformity.
Based on patient's history, clinical symptoms, and radiographic findings, a diagnosis of osteoradionecrosis is determined.
- Bisphosphonate-related jaw necrosis
Common Initial Treatments
Dental treatment prior to radiation therapy to prevent osteoradionecrosis
- All extractions should be done 3-6 weeks prior to initiation of radiation therapy to allow for adequate healing.
- Perform adequate alveoloplasty after dental extractions to eliminate sharp bony projections.
- Do not overstretch the mucosa and achieve primary closure.
- If dental extraction was done because of severe periapical infection, prescribe antibiotics e.g., penicillin V potassium 500mg (dispense 28 tablets, take 1 tablet 4times/day) or Amoxicillin 500 mg (dispense 28 tablets, take 1 tablets 4 times/day to reduce risk of infection
Dental treatment after radiation therapy to prevent osteoradionecrosis
- Due to the risk of osteoradionecrosis, avoid invasive surgical procedures, involving exposure of irradiated bone for at least 6-12 months after radiation treatment.
- If tooth extraction is unavoidable, exercise extreme caution while extracting the tooth. Conservative surgical technique and antibiotic coverage should be given to assure complete healing.
- Perform minor debridement, eliminating sharp bone edges, sharp tooth surfaces.
- Advise patient to maintain local hygiene of the area of exposed bone with topical antibacterial agents, such as chlorhexidine gluconate 0.12% (dispense 1 bottle rinse with 20 ml for 30 seconds 3 times/day).
- To control secondary bacterial infections:
- Prescribe Penicillin V potassium 500mg (dispense 28 tablets, take 1 tablet 4 times/day).
- Alternatively, prescribe Amoxicillin 500 mg (dispense 28 tablets, take 1 tablets 4 times/day) or Clindamycin 150mg or 300 mg (dispense 150 to 300 mg (dispense 28 capsules, take 1 capsule every 6 hours).
- For pain control: prescribe acetaminophen 325 mg, taken every 4 hours.
- Conservative bone sequestromy may be required in extensive cases in consultation with an oral surgeon.
- Surgical removal of large areas of necrotic bone may be required in consultation with an oral surgeon.
- Avoid spicy foods and use over-the-counter mouthwashes to maintain proper oral hygiene, and non-prescription local anesthetics, if required.
- Neville BW, Damm DD, Allen CM, Bouquot JE, editors. Oral and maxillofacial pathology. 3rd ed. St. Louis: Saunders Elsevier; 2009.
- White SC, Pharoah MJ. Oral radiology: Principles and interpretation. 6th ed. Mosby; 2008.
- Annane D, Depondt J, Aubert P, Villart M, Géhanno P, Gajdos P, et al. Hyperbaric oxygen therapy for radionecrosis of the jaw: a randomized, placebo-controlled,double-blind trial from the ORN96 study group. J Clin Oncol. 2004;22(24):4893-4900.
- Wahl MJ. Osteoradionecrosis prevention myths. Int J Radiat Oncol Biol Phys. 2006;64(3):661-669.