1Department of Mechanical and Industrial Engineering, University of Massachusetts, Amherst, 2Department of Anthropology, University of Massachusetts, Amherst, 3Department of Biology, University of Massachusetts, Amherst
Thursday 9:15-9:30, Broadway III/IV
In an effort to understand how occlusal tooth morphology relates to diet, researchers have studied tooth relief and the radius of curvature of cusps. Parametric models of teeth have been built and engineering concepts used to optimize tooth designs; those morphologies have been sought in nature. Idealized morphologies do not correlate with diet with a high level of consistency, perhaps because in nature structural strength in the tooth overrides idealized morphology.
Here we present a parameterized finite element (FE) model to simulate the contact mechanics of a bunodont molar interacting with a large hard food item. Parameters assigned to this model include radius of curvature of all four cusps in both buccolingual and mesiodistal directions. For this study, the radii of curvature were varied and FE analysis simulations were run. We applied a force of 2 kN to the molar, which was made to bite into a large, hemispherical substitute food item which consistently had a radius of curvature significantly greater than the radii of curvature of the cusps.
We predicted that radii of curvature would be positively correlated with the tensile stresses in the tooth and negatively correlated with the tensile stresses in the food item. This was true for stresses in the tooth but not the food item. This is because as the radii of curvature in the cusps decreased, the contact area between the tooth and food item increased due to the shape of the valley between the cusps.
This project was funded by grants from the National Science Foundation Physical Anthropology HOMINID program (NSF BCS 0725078 and 0725126) and the Biomesh grant (NSF BIO 0743460).