| Budget Amount *help |
¥4,600,000 (Direct Cost: ¥4,600,000)
Fiscal Year 1993: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1992: ¥3,700,000 (Direct Cost: ¥3,700,000)
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| Research Abstract |
Many diseases such as inflammation and tumor occur in oral regions. The recovery of nerve distribution after the therapy would be interesting neurobiolgically. Models for marginal periodontitis and tongue cancer were prepared experimentally, and the distribution of nerves during tissue destruction and after therapy were examined. 1. Gutta-percha points were inserted in the interdental papilla of rat molars, and the compression of points induced periodontitis. The papilla lost epithelial layr and was followed by inflammatory infiltrates and the disappearance of interdental horizontal ligaments. Subsequently the height of interdental septa was decreased by the resorption of bone. Most of nerve fibers in inflammatory focus degenerated or disappeared, but a few intact fibers were preserved. after the removal of points, inflammation subsided and the outline of interdental papilla were gained by the proliferation of granulation tissue. Regeneration of horizontal ligament and epithelial layr were observed, but epithelial attachment remained to be shifted periapically, and interdental septa could be recovered incompletely. Although the regeneration of nerve fibers could be observed both in the periodontal ligament and interdental papilla, their amount were less scarce compared with the tissues of the control. 2. VX_2 carcinoma cells were transplanted in the rabbit tongue. Degenersation of lingual tissues were observed with the proliferation of carcinoma cells. Nerve fibers showed swelling, granulation and fragmentation at the periphery of and anterior to the tumor mass, while degeneration, atrophy and disarrangement of muscle fibers were observed in the lingual tissue anterior to the mass. After the surgical resection of tumor, degeneration and disappearance of nerve fibers were markedly observed at the surgical edge and the tip of the tongue, followed by the decrease of nerve distribution. Long interval after surgery provoked regeneration of nerve fivers, the amoun
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