| Project/Area Number |
07838036
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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 | 時限 |
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| Research Field |
咀嚼
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| Research Institution | Showa University |
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Principal Investigator |
MAKI Koutaro Showa univ., Dent., Assistant Prof., 歯学部, 講師 (80219295)
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| Co-Investigator(Kenkyū-buntansha) |
INOU Norio Tokyo Institute of Technology, Dept, of Mechanical Informatics, Assistant Prof, 工学部, 助教授 (70126308)
SHIBASAKI Yoshinobu Showa univ., Dent., Prof., 歯学部, 教授 (40014005)
三河 雅敏 昭和大学, 歯学部, 助手
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1995: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Bone Density / Mechanical Stress / Masticatory System / Computed Tomgraphy / Finite Element Method / 機能的刺激 / バイオメカニクス / 顎骨 / 成長発育 / 咀嚼 / FEM |
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| Research Abstract |
The purpose of this study was to investigate the age-related changes in the bone density distribution and to clarify the mechanism of mandibular deformity using 3-dimensional quantitative CT (3DQCT) and a 3-dimensional Finite Element Method (3DFEM).
Forty-seven individuals with skeletal deformity and twenty normal subjects (6 to 27 years old) were evaluated.
The results obtained from the 3-dimensional abservation of bone density and the FE analysis were as follows : Most cases of deformed mandibles under 18 years of age showed high-density deviation which coincided with the morphological displacement. However, in subjects more than 20 years old, high-density areas were arranged symmetrically against the morphological deformation. The distribution of equivalent (mieses) stress generated by muscle loading coincided with the bone density. In normal subjects and deformed subjects over 20 years old, symmetrical stress distribution was observed. However, in deformed mandibles under 18 years old, stress distribution was biased toward the affected side.
Based on this comparison of normal and deformed subjects, the mechanical stress generated by masticatory muscles affects the distribution of mandibular bone density and leads to morphological changes in growth. The skeletal deformity which appeared during postnatal growth was caused by imbalanced mastication. However, after condylar growth was complete, mandibular bone density adapted to its imbalanced mechanical environment. These findings suggest that preventive, orthodontic treatment, such as eliminating the functional interference of the malocclusion at an early stage, should give successful results.
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