1997 Fiscal Year Final Research Report Summary
The mechanism of Tissue Response in Orthodontic Tooth Movement
| Project/Area Number |
07407059
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
矯正・小児・社会系歯学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
ISHIKAWA Hiroyuki Hokkaido Univ., Dental Hospital, Lectuer, 歯学部・附属病院, 講師 (20184492)
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| Co-Investigator(Kenkyū-buntansha) |
SATOH Yoshiaki Hokkaido Univ., Sch.of Dent., Instructor, 歯学部, 助手 (00250465)
YAMAMOTO Katsuyuki Hokkaido Univ., Fac..of Eng., Prof., 工学部, 教授 (10088867)
WATARI Fumio Hokkaido Univ., Sch.of Dent., Prof., 歯学部, 教授 (70158682)
WAKITA Minoru Hokkaido Univ., Sch.of Dent., Prof., 歯学部, 教授 (40018916)
NAKAMURA Shinji Hokkaido Univ., Sch.of Dent., Prof., 歯学部, 教授 (80001791)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Tooth Movement / Osteoc last / Degenerated Tissue / Periodontal Ligament / Stress Analysis / Elastic modulus / Tissue Response / Bone Resorption |
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| Research Abstract |
The purpose of this study was to investigate the mechanism of tissue response in orthodontic tooth movement from histological observation, the analysis of stress distribution, and the analysis of tooth movement. The results obtained ware :
1.Rear bone resorption seemed to depend on stress distribution and circulatory conditions in the perforating channels from bone marrow to periodontal space.
2.The remaining bone and degenerated tissue in response to initial orthodontic force influenced stress distribution in the periodontal tissue due to the subsequent readjusted force.
3.The specimen-specific finite element analysis showed that the osteoclast appearance and the formation of degenerated tissue are closely related to a specific level of the compressive stress in the periodontal ligament.
4.The elasticity of the periodontal ligament was evaluated with a mechanical test machine developed. The elastic moduli of the periodontal ligament determined from the tensile and compressive tests under quasi-static conditions were 0.37(]SY.+-。[)0.11 and 0.079(]SY.+-。[)0.017MPa, respectively.
5.The alveolar bone resorption rate was estimated from the clinical measurements of tooth movement and the finite eIement analysis. The rate to a unit stress was found to be 0.58(]SY.+-。[)0.16 mum/(kPa・day).
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