Mechanical Analysis of the Upper Molar Tooth of African Apes Using the Finite Elements Method

DOI Web Site 23 References Open Access
  • SHIMIZU Daisuke
    Laboratory of Physical Anthropology, Department of Zoology, Graduate School of Science, Kyoto University

Bibliographic Information

Other Title
  • 現生アフリカ類人猿における上顎大臼歯歯冠形態の有限要素法による力学的解析
  • ゲンセイ アフリカ ルイジンエン ニ オケル ジョウガク ダイキュウシシカン

Search this article

Description

Teeth of primates must reduce the risk of the fracture under cyclic load during masticating various foods, through their lifespan. I examined the relationship between the shape of the molar teeth and both magnitude and distribution of stress under various loadings in African apes by finite elements stress analysis (FESA). I modelled the occlusal shape of the upper first molar of African apes (chimpanzee, bonobo and gorilla) in two-dimensional plane that dissects the tooth buccolingually passing the tips of two mesial cusps. The parameters of this simplified model for each African apes can effectively discriminate the species. The FESA was applied to the model.<br>Four types of load were applied to this two-dimensional model simulating mastication of the following four kinds of foodstuff: 1) large brittle 2) tender 3) soft and ductile 4) small brittle. No significant difference about the pattern of stress was observed in these three apes. However the maximum value of equivalent stress differed significantly. Under all type of loading, gorilla indicated the largest value of maximum equivalent stress. This result seems to reflect that the morphology of the gorilla's molar tooth is most specialised to “shear” fibre-rich diets among these African apes. Despite of the relatively large maximum equivalent stress, it is unlikely that gorilla has a high risk of the tooth fracture compared with chimpanzee and bonobo. Thus, it is suggested that the molar tooth of the African apes is designed highly safely against the mechanical loads during mastication.

Journal

  • Primate Research

    Primate Research 14 (3), 153-163, 1998

    Primate Society of Japan

References(23)*help

See more

Details 詳細情報について

Report a problem

Back to top