Quantifying molar tooth shape in primates using geometric morphometrics
| Project/Area Number |
14540661
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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 |
人類学(含生理人類学)
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| Research Institution | Showa University |
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Principal Investigator |
KONDO Shintaro Showa University, School of Dentistry, Lecturer, 歯学部, 講師 (60186848)
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| Co-Investigator(Kenkyū-buntansha) |
NATORI Masahito Okayama University of Science, Associate Professor, 総合情報学部, 助教授 (30189188)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2002: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | primates / geometric morphometrics / Macaca / molar / deciduous premolar / Procrustes / thin-plate sprine / landmark / 旧世界ザル / 場の理論 / 支持咬頭 / 誘導咬頭 / ニホンザル / プロクルステス法 / 形態計測 / 薄板スプライン / ランドマーク / 歯冠細部構造 / 近遠心径 / 頬舌径 |
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| Research Abstract |
The occlusal shapes of molars in Macaca fuscata fuscata were analyzed by means of geometric morhpometrics. The central pit was selected as the origin, and the following points were selected as landmarks the cusp tips, the mesial and distal pits, and the intersection between central groove and buccal/lingual groove, and the most prominence points of occlusal outline. The two dimensional and three dimensional vectors for the landmarks were measured.
Two dimensional measurements were made for the three permanent molars (M1, M2 and M3), and they were analysed by the Procrustes and thin-plate spline analyses. Sexual differences in molar shape were very small, but centroid size was significantly different between the two sexes. Sexual differences in size and shape of the molars were more conspicuous in the later-developed molar than in the early-developed molar. There were small differences between M1 and M2 in shape, but M2 had significantly larger centroid size than M1. The shape change from M1 to M3 is represented by mesiodistal elongation and buc colingual compression of the distal half of the crown.
The occlusal shape differences between maxillary fourth deciduous premolar (dp4) and first permanent molar (M1) were analyzed by the thin-plate spline analyze. Three dimensional vectors of 8 landmarks were measured when the central pit was selected as the origin. The centroid size of the dp4 was significantly smaller than the M1 (P<0.01). The dp4 had shallower pits and well-developed metacone than M1, but the location of cusp tips on the occlusal plane did not different among the two molars.
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Report
(4 results)
Research Products
(3 results)
