THE EXPERIMENTAL STUDY OF EARLY IRRADIATION EFFECTS ON THE TEMPOROMANDIBULAR JOINT IN WHITE RAT

방사선 조사가 백서 악관절에 미치는 조직병리학적 조기변화에 관한 실험적 연구

The purpose of this study was to investigate the early effects of irradiation on the temporomandibular joint in rats. Male rats were singly irradiated with the dose of 5 Gy or 10 Gy to their head and neck region by /sup 60/Co X ray. Experimental animals were sacrificed at each of the following time intervals -1, 2, 3, 5, 7 and 14 days. The specimens were examined with a light microscope, and treated with H & E staining and immuno-histochemical staining. The results were as follows, 1. By light microscopic findings, proliferative and hypertrophic zone were narrowed and hematopoietic cells were few in number at 5 days after irradiation. Repair signs were seen at 7 days after irradiation when decrease in osteoclast, increase in hematopoietic cells and increase of proliferative zone were noted. The 10 Gy irradiated group showed more severe histopathologic change than the 5 Gy group, and their repair was more slow. 2. In the S -100 antibody, positive cells were examined in the glenoid fossa. Positive cells of irradiated group showed more slight decrease in number than the control group. Low radiosensitivity and slow repair was noted in the glenoid foosa. 3. The interarticular disc was high radioresistant, and any histopathologic changes were not seen in disc. 4. Repair was examined clearly with the response to the antibodies. Especially by 5 days after irradiation 5 Gy group showed S-l00 positive cells in hypertrophic zone next to proliferative zone, chondroitin-4-sulfate positive cell in erosive zone next to hypertrophic zone, type-1 collagen positive cell in subchondral bone.