Osteoradionecrosis

Osteoradionecrosis of Jaw Bones

• It is also known as Radiation Osteomyelitis. 
• It is known as the most serious, late complication of therapeutic radiotherapy (RT) for head and neck (H and N) cancer, as it produces considerable morbidity.
• Necrosis of the jaw bone as the result of radiation is the complication of the radiotherapy.
• When the jaws are exposed to overdoses of radiotherapy during treatment of oral cancer, the normal bone cells lose their repair and regeneration potential. (A total dosage of approximately 6500 to 7000 uGy or greater, particularly to the floor of the mouth and mandible significantly show elevated incidence of ORN of the mandible.)
• Massive doses of radiation may cause necrosis of the bone due to thrombosis of blood vessels.

Definition:

Osteoradionecrosis (ORN) is an exposure of nonviable, nonhealing, nonseptic lesion in the irradiated bone, which fails to heal without intervention. It is a sequelae of irradiation induced tissue injury, in which hypocellularity, hypovascularity and hypoxia are the underlying causes.

Clinical Features:

1. Severe, deep, boring pain in the jaw
2. Swelling of the face when infection develops
3. Soft tissue abscess and draining sinus
4. There is breakdown of the soft tissues leading to denaturation of large area of bone
5. Trismus
6. Fetid odor
7. Pyrexia
8. Pathological fracture
9. There is Xerostomia and radiation caries.
10. In children, deciduous teeth eruption is delayed and so is exfoliation.
11. Developing root of permanent tooth may be reduced in size.

Treatment:

It may be divided into :

1. Prophylactic
2. Medicinal, and
3. Surgical

Prophylactic:

• All foci of infection should be removed before radiation of the jaw.
• All dead tooth or tooth with deep caries should be extracted.
• All retained roots, periodontally affected teeth, unrestorable teeth in line of radiation should be extracted.
• Thorough oral prophylaxis is recommmended.
• Fluoride therapy is used for the prevention of radiation caries.
• Patient who undergoes radiation should  not undergo any surgeries in the maxillofacial region.
• Extraction shouldn't be done in heavily irradiated jaw.

Medicinal:

• Broad spectrum antibiotic - local use of antibiotic.
• Good oral hygiene and use of 0.2 percent aqueous chlorhexidine mouthwash decreases secondary infection of any
• ulcerated mucosa, reduces plaque accumulationand caries.

Surgical:

• Sequestrectomy and resection of  the jaw
• The dead space is separated with the help of Gigli's saw or surgical bur.
• The continuity of the jaw is maintained with the help of reconstruction plate.