THE EXPERIMENTAL STUDY OF $^{60}Co$ IRRADIATION EFFECTS ON THE MANDIBULAR CONDYLE AND MANDIBULAR GROWTH IN WHITE RAT

$^{60}Co$ 조사가 백서의 하악과두와 하악골 성장에 미치는 영향에 관한 실험적 연구

  • Kang Tai Wook (Department of Oral Radiology, College of Dentistry, Seoul National University) ;
  • You Dong Soo (Department of Oral Radiology, College of Dentistry, Seoul National University)
  • 강태욱 (서울대학교 치과대학 치과방사선학교실) ;
  • 유동수 (서울대학교 치과대학 치과방사선학교실)
  • Published : 1991.12.01

Abstract

This study was performed to understand the irradiation effects on the mandibular condyle and mandibular growth in developing white rats. Forty eight white male rats of the Sprague-Dawley strain aged 4 weeks, were devided into two groups; control group and experimental group. A single target dose of l0Gy of radiation was given to the mandibular condylar area and the observations of the photo analysis, radiologic, histopathologic and immunohistochemical study revealed as follows; 1. Animals killed one week after irradiation showed lesser increase in body weights, no difference in photo analysis and decreased thickness of cartilagenous layers of the condyle than the control group. 2. Two weeks after irradiation the weight increases were almost same in both irradiated and control groups and in photo analysis, the distance from Mental Foramen to Incisal tip (Mf-It) was longer than the controls. Repair processes were taken place in irradiated group, but the cartilagenous layers were thinner than the controls. 3. By the third week after exposure further repair was seen in the trabeculae and the distance from Condylion to Mandibular plane (Cd-Cd') was longer than the controls and the weight increases were almost same as the controls. 4. At 4 weeks after irradiation the cells of proliferating zone repaired to almost normal findings, but the cartilagenous cell layers were still thinner than the control animals. In photo analysis, the distances from Menton to Anterior Notch (Me-An), from First Molar to Mandibular plane (Fm-Fm') were shorter and the weight increases were lesser than the controls. 5. In the S-100 antibody, the positive cells were increased in number, but decreased reactivities were seen at the proliferating zone of the irradiated groups. In the Monoclonal Anti-Proteoglycan antibody and Type Ⅰ collagen antibody, the irradiated groups showed little decreased number of positive cells and in the Type Ⅱ collagen antibody, the differences between irradiated and control groups were undetectable in immunohistochemical study.

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