Meeting Abstract
Normal cranial growth and development rely on appropriate tissue interactions. Soft tissues like the brain and eyes develop first, becoming enclosed by fibrous capsules (e.g. periosteum, dura) within which the skeletal units develop, and are maintained and shaped. However, with the exception of the jaw muscles, most biomechanical models do not take into account the influence of soft tissues on patterns of cranial strain. Previous work has highlighted the need for a more comprehensive analysis of the biomechanical role of cranial soft tissues in both reptiles and mammals. We aim to clarify and quantify the role of apparently passive cranial soft tissues, including the brain, skin, eyes, sutures, and fascia, in a rat biomechanical model. Using 3D computer-based mechanical simulations based on micro-CT and detailed muscle dissections, we combined multibody dynamics analysis and finite element analysis to investigate and compare strains in skulls with and without soft tissues. The model was also validated against bite force data collected in vivo. Sutures redistribute cranial strain and have a greater effect on both strain magnitude and distribution than other soft tissues. Our model showed that including anatomically detailed sutures is important for modelling cranial strain. However, more research is needed to fully understand their significance, including comparisons with other species and juvenile individuals. Future research will aim to determine the relative significance of different soft tissues in reptiles versus mammals. We predict that soft tissues may play a greater overall role in the frame-like skulls of reptiles.
