幼若期下顎骨の放射線障害に関する実験的研究
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概要
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The mandible (dentition of immature permanent) young adult dogs was irradiated for 3, 000R with X-ray of 200 kVp and radiation hazard to the mandibles was investigated radiologically, photographically, pathohistologically at one week, two weeks, one, two, four, six, and eight months after irradiation. The results were as follows : 1. Radiological findings 1) Effect of irradiation on root formation was observed until 1 month after irradiation. Thereafter, apical obliteration was observed. 2) Lamina dura in the periodontal membrane space disappeared at 2 months but was observed in part at 8 months. 3) The alveolar bone (at root bifurcation region) showed resorption of the alveolar crest and bone resorption in moth-eaten appearance at 2 months, and formation of sequestrum and bone fracture at 4 months. From 6 months, osteosclerotic image was observed in the resorption image ; yet bone defect image was observed in the inferior portion of the alveolar bone. 4) Almost all cortical bone was resorbed at 6 months and a fall in radiopacity was observed on the whole. 2. Photographical findings Microphotograms showed a fall in densitometric curve of the alveolar bone at root bifurcation region at 1 month. However, the densitometric curve of the alveolar bone rose at 6 months. The curve for the inferior region of the alveolar bone was a falling type with very irregular undulations. 3. Pathohistological findings 1) Almost all buccal cementum disappeared at 4 months. However, regeneration image of cementum was observed from 6 months. 2) The buccal connective tissue in the periodontal membrane space ran irregularly at 2 weeks and the periodontal membrane space disappeared completely at 4 months. However, the lingual periodontal membrane was irregular arrangement of connective tissue. Bundle bone showed resorption image at 2 weeks and the buccal bundle bone disappeared at 2 months. At 8 months, however, new bundle bone was observed. 3) The cortical bone at 2 weeks showed empty lacunae on the buccal side. At 4 months, resorption image of Haversian canalis was seen in every cortical bone. At 8 months, Haversian canalis appeared buccolingually and resorption image such as new lacunae was observed. 4) Fatty marrow was already formed in bone marrow at 1 week. At 8 months, fatty marrow was seen on the whole. 5) In the inferior alveolar artery, irregular arrangement, extention, and proliferation of elastic fivers were seen and rupture and disappearance of ring form were observed in the mesothelium.
- 九州歯科学会の論文
- 1986-02-25