Meeting Abstract

90.9  Thursday, Jan. 7  Multidimensional analysis of mandibular function in Alligator mississippiensis using geometric morphometrics and finite element modeling REED, D.A.*; PORRO, L.B.; HOLLIDAY, C.M.; LEMBERG, J.B.; METZGER, K.A.; ROSS, C.F.; The University of Chicago; The University of Chicago; The University of Missouri; The University of Chicago; Hofstra University; The University of Chicago dreed@uchicago.edu

Quantifying deformation patterns in the vertebrate mandible allows hypotheses relating morphology to function to be tested. Deformation patterns were quantified in the mandible of a sub-adult Alligator mississippiensis using both finite element analysis (FEA) and in vivo strain gage analysis. FEA compliments in vivo strain gage analysis by allowing hypotheses of functional morphology to be extended to global deformation patterns tested under repeatable and controlled conditions. Additionally, FEA can produce results in hypothetical models, such as models of identical geometry but varying elastic material properties and anisotropy. Forty such hypothetical models were loaded under identical initial conditions, varying only in the elastic material properties or anisotropy of the bones and sutures. Variance in the global deformation pattern was evaluated using geometric morphometric analyses. Principal component plots of the deformed models found each to occupy a distinct area of the plot. Increases in the stiffness of both bone and sutures resulted in decreases in PC1, toward the space on the plot occupied by the undeformed model. When anisotropy was introduced to the deformed model, it was found to occupy an area of the plot distinct from that of isotropic bone and sutures. These results indicate that both the stiffness and anisotropy of bones and sutures impact the global deformation of the model in distinct and measureable ways.