| Project/Area Number |
11672006
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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 |
Surgical dentistry
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| Research Institution | SHOWA UNIVERSITY |
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Principal Investigator |
SHIROTA Tatsuo School of Dentistry, SHOWA UNIVERSITY Assistant Professor, 歯学部, 講師 (60235760)
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| Co-Investigator(Kenkyū-buntansha) |
OHNO Kohsuke School of Dentistry, SHOWA UNIVERSITY Associate Professor, 歯学部, 助教授 (30112725)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Osteoporosis / Bone Mineral Density / Mandible / Ovariectomy / Histomorphometry / 家兎 / 卵巣摘出 / 下顎骨 / 骨形態計測 |
|---|
| Research Abstract |
Numerous clinical studies have suggested that the greater risk for oral bone loss in females may be correlated with osteoporosis after menopause. Experiments of titanium implantation on ovariectomized rats' tibiae revealed less bone-implant contact. However, it is necessary to obtain the information in experimental studies to determine the relationship between oral bone loss and osteoporosis with loss of ovarian function. The purpose of this study was to evaluate the association between loss of ovarian function and the bone mineral density changes in the mandibular edentulous bone of ovariectomized rabbits by peripheral quantitative computed tomography.
Twenty-four adult female Japanese white rabbits were used in this experiment. The mandibular incisors were initially extracted to create implant bone. Twelve animals were bilarterally ovariectomized and the other twelve sham-ovariectomized 12 weeks after tooth extraction. All rabbits were sacrificed at 4 and 12 weeks after ovariectomy and sham-ovariectomy with 6 rabbits in each of the four resultant groups. After the edentulous parts of distal mandibular bodies were measured by peripheral quantitative computed tomography, the mandibles were processed undecalcified and examined by quantitative trabecular bone histomorphometry. There were significant decreases in total bone mineral density and trabecular bone mineral density in the mandibles of rabbits at 12 weeks post-ovariectomy. Also, there were significant decrease in trabecular number, osteoid width, eroded surface and mineral appositional rate. These results demonstrate the mineralized bone loss in the mandibles of ovariectomized rabbits and suggest the same loss in postmenopausal patients.
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