| Project/Area Number |
10671849
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
補綴理工系歯学
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| Research Institution | Matsumoto Dental University |
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Principal Investigator |
IGARASHI Yoshimasa Matsumoto Dental University, School of Dentistry, Dept. of Prosthodontics, Professor, 歯学部, 教授 (20107303)
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| Co-Investigator(Kenkyū-buntansha) |
OGATA Akira Matsumoto Dental University, School of Dentistry, Dept. of Prosthodontics, Assistant, 歯学部, 助手 (70233400)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | partially dentate patients / posterior occlusal support / masticatory performance / Bonwill triangle / jaw tracking system / biting force / condylar heads (condyles) / ATP analyzer / 欠損歯列 / 補綴処置 |
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| Research Abstract |
The aim of the restoration of partially dentate patients has oriented to the normal healthy dentition with 28 teeth. However, Kayser and Kalk of the Netherland recently advocated new idea against to above conventional one. That is ; Human mandible will not displace to the level of initiating any of the pathological changes if the posterior occlusal supports are maintained at least to the second premolar contacts for the normal jaw function and masticatory performance especially in the old individuals.
In this present study, we wished to assess above two diverse theories for our clinical diagnostic base. Number of volunteers who needed the restoration of posterior occlusal surface contacts in both premolars and molars with fixed restorations joined to the investigation. Three dimensional changes of the jaw relationships before and after removing the posterior restorations in turn at every maximal clenching were recorded. Displacements of the Bonwill triangle were recorded by the jaw trac
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king system (MMJI-II SHOFU-Co. Japan). Biting force was recorded at every condition by computorized bite-force meter (Occluzer GC-Co JAPAN). Though, results in every individual differed to some extent, it was pointed out as a whole that according to progressive loss of the posterior occlusal supports, both condylar heads (condyle) moved from upward and forward directions. This tendency increased gradually according to the successive loss of posterior occlusal contacts. Biting force reduced in every individual according to the loss of posterior occlusal contacts.
We concluded that in individuals with reduced posterior occlusal contacts, the displacement of the mandible would take place even with small occlusal force like habitual clenching without posterior prostheses against normal individuals. We tried to use the ATP analyzer for assessing individual masticatory performances. We have to continue the investigation of this problem for further evidence in prosthetic rehabilitation for partially dentate patients with EBM basis. Less
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