Chronic Osteomyelitis

[Anonymous]

ORN can be either spontaneous or the result of an insult. Spontaneous ORN occurs when, in the process of otherwise normal turnover of bone, the degradative function exceeds new bone production. ORN develops following injury when the reparative capacity of bone within an irradiated field is insufficient to overcome an insult. Bone injury can occur through direct trauma (eg, tooth extraction [84%], related cancer surgery or biopsy [12%], denture irritation [1%]) or by exposure of the irradiated bone to the hostile environment of the oral cavity secondary to overlying soft tissue necrosis. The cumulative progressive endarteritis caused by radiotherapy results in insufficient blood supply (tissue oxygen delivery) to effect normal wound healing

        

[sushantpatel_doc]

Clinical symptoms include the following:

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Pain
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Swelling
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Trismus
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Exposed bone
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Pathologic fracture
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Malocclusion
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Oral cutaneous fistula formation

On physical examination, missing hair follicles, surface texture changes, and color changes are common findings that assist clinicians in assessment of the area of radiation injury.

In a histologic study of irradiated osteoradionecrotic mandibles, several characteristic changes were noted. The inferior alveolar artery (the predominant arterial blood supply to the body of the mandible) and periosteal arteries had significant intimal fibrosis and thrombosis. Normal marrow was replaced by dense fibrous tissue with loss of osteocytes. Finally, the study noted buccal cortical necrosis with sequestrum formation and periosteal fibrosis with a tendency to detach from the cortex.[4] In the elderly, the inferior alveolar artery’s flow to the mandible diminishes and the periosteum and muscle attachments predominate as the primary blood supply. The thrombosis of the inferior alveolar artery and surgical disruption of this soft tissue blood supply may contribute to the development of osteoradionecrosis (ORN)

        

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