Bone vitality in the cat's irradiated jaw. Histological study

The vitality of the mandible in cats was studied from two to 15 months after irradiation. Dose of 80 Gy in three days was delivered using three hairpin shape iridium-192 wires surrounding the mandibula. The osseous vitality was assessed from the percentages of lacunae inhabited by osteocytes (IL). The results are compared with those obtained by microradiography. At two months, a small reduction of vitality is already observed, it becomes progressively more important. At one year, vitality is recovered nearly fully in the ventral part of the mandibula, mainly at the level of the alveolar crest. Vitality remains reduced in the dorsal part. Microradiographic lesions appear more slowly; they are apparent at six months.