| Project/Area Number |
06672045
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
矯正・小児・社会系歯学
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| Research Institution | Niigata University |
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Principal Investigator |
KOHNO Misako Niigata Univ. Dental Hospital, Asistant Professor, 歯学部・附属病院, 助手 (60153491)
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| Co-Investigator(Kenkyū-buntansha) |
SAKU Takashi Niigata Univ. School of Dentistry, Professor, 歯学部, 教授 (40145264)
NODA Tadashi Niigata Univ. School of Dentistry, Professor, 歯学部, 教授 (00013970)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1994: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Odontomas / Extracellular matrix / Stromal tissue / Pericoronal tissue / Delayd tooth eruption / Gingive / Infancy / Hamartomatous lesions |
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| Research Abstract |
We obtained following results in this research.
1) Immunohistochemical analysis of human odontomas : We studied immunohistochemical localizations of extracellular matrix proteins in odontomas in comparison with those of normal teeth. Each dental component of odontomas showed different composition patterns of stromal molecules, that might result from some disturbance during the tooth germ development.
2) Immunohistochemical analysis of the pericoronal tissues of teeth delayd in eruption : Among the 60 specimens, odontomas were found in 23 ; 29 (48.4%) showed common characteristic features of myxofibrous hyperplasia (MH) ; 8 were ameloblastic fibroma-like lesions (AF). In the lamina propria above MH or AF,there was tenascin-rich fibrosis, indicating that such lesions might induce the overlying gingiva to active remodelling. AFs as well as MH were regarded as hamartomatous lesions because they were found in nodules without any definite capsulation and they were often continuous with their atrophic forms, some of which were undergoing spontaneous retraction. We concluded that the presence of MH-or AF and consequent gingival fibrosis may be one of the major local factors causing delayd tooth eruption.
3) Experimental odontomas in osteopetrotic op/op mice : We examined odontoma-like malformation at the incisor roots of op/op mice immunohistochemically. The odontoma-like malformations resulted from interruption of growing tooth germs by bony trabeculae which were not in remodelling processes and from scanty or poorly developed extracellular martrices between tooth germs and bones. Our conclusion was that an enough space of dental sac and an appropriate arrangement of extracellular matrices were important for normal tooth development. This research revealed some possible causes for failures in tooth germ development and tooth eruption.
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