THE ROLE OF TOOTH ENAMEL MECHANICAL PROPERTIES IN PRIMATE DIETARY ADAPTATION
Paul Constantino, James J. Lee, Yvonne B. Gerbig, Adam Hartstone-Rose, Mauricio Talebi, Brian R. Lawn, Peter Lucas
Primate teeth adapt to the physical properties of foods in a variety of ways including changes in occlusal morphology, enamel thickness, and overall size. We conducted a comparative study of extant primates to examine whether their teeth also adapt to foods through variation in the mechanical properties of the enamel. Nanoindentation techniques were used to map profiles of elastic modulus and hardness across tooth sections from the enameldentin junction to the outer enamel surface in a broad sample of primates including apes, Old World monkeys, New World monkeys, and lemurs. The measured data profiles feature considerable overlap among species, indicating a high degree of commonality in material properties. These results indicate that differences in the load-bearing capacity of primate molar teeth are more a function of morphologyparticularly tooth size and enamel thicknessthan of underlying material properties.