Finite element modeling of occlusal variation in durophagous tooth systems

In addition to breaking hard prey items, the teeth of durophagous predators must also resist failure under high loads. To understand the effects of morphology on tooth resistance to failure, finite element models were used to examine differences in total strain energy (J), first principal strain and the distribution of strains in a diversity of canonical durophagous tooth morphologies. By changing the way loads were applied to the models, I was also able to model the effects of large and small prey items. Tooth models with overall convex morphologies have higher in-model strains than those with a flat or concave occlusal surface. When a cusp is added to the tooth model, taller or thinner cusps increase in-model strain. While there is little difference in the relationships between tooth morphology and strain measurements for most models, there is a marked difference between effects of the large and small prey loads on the concave and flat tooth morphologies. Comparing these data with measurements of force required by these same morphologies to break prey items illustrates functional trade-offs between the need to prevent tooth failure under high loads by minimizing in-tooth strain versus the drive to reduce the total applied force.