Meeting Abstract

P1.138  Monday, Jan. 4  Strain accommodation in the zygomatic arch of the pig (Sus scrofa) in vitro and in silico. BRIGHT, J.A.*; GRÖNING, F.; University of Bristol; University of York j.bright@bristol.ac.uk

It has been suggested that mammalian cranial sutures act to reduce the levels of strain experienced by the skull during feeding. A complete skull of a domestic pig was loaded and strains in the zygomatic arch were investigated using Digital Speckle Pattern Interferometry (DSPI), a full field strain measurement technique offering several advantages over the more traditional use of strain gauges. The zygomatic arch was chosen for the presence of a large and patent suture, and the skull was loaded incrementally on a testing rig that flexed the skull dorso-ventrally. Interference fringes were recorded after each step, from which the strain distribution was calculated. The zygomatic suture is clearly visible as a region of highly localised, increased strain in DSPI-produced contour plots. DSPI also distinguishes differences in the magnitude of deflection experienced by the two adjacent bones, supporting the theory that it may be acting to accommodate deformation and thereby minimise bone strain. Finite Element Analysis (FEA) of the same specimen is able to reproduce similar patterns of strain, but is dependant on how the suture is modelled: including soft tissues always reduces the overall strain, but while joining the suture with spring elements replicates strain patterns of an open-suture model, joining it with tetrahedra replicates patterns of a solid model, and is more similar to patterns observed using DSPI. DSPI therefore provides a means of validation for the FE models, and here highlights the importance of correctly modelling the soft tissues when including sutures in FEA.