Radiation Tissue Damage – Osteoradionecrosis (ORN)

Osteoradionecrosis (ORN) is the circumstance of non-vital bone in a site of radiation injury.  ORN although spontaneous is generally resulting from tissue injury.  Clinical symptoms of ORN include the following:  malocclusion, pathologic fracture, pain, trismus, swelling, exposed bone and oral cutaneous fistula formation. 

Mandibular ORN can also develop generally after local trauma procedure like periodontal procedure, dental extractions, related cancer surgery and biopsies.

Radiation injury can be determined by physical examination with findings such as missing hair follicles, surface texture change and color changes.

There are two direct intervals that exist in which prudent clinical practice can reduce the occurrence of ORN.  One is in the pretreatment phase and the second is in the rehabilitation phase. Hyperbaric oxygen is among the most studied and frequently reported applications in the treatment of delayed radiation injuries. Hyperbaric oxygen therapy has been used along with surgery and has demonstrated successful resolution of mandibular ORN in patients using a staged protocol with HBO and surgery.  Hyperbaric oxygen is effective in radiation injury. HBO2 induces neovascularization in hypoxic tissues. Development of ORN is quite risky and is in relation to the radiation dose.  The risk of developing ORN typically continues through out the patient’s life.