Thesis (M.D.S. 1979) from the Department of Dental Health, University of Adelaide.

Thesis (M.D.S. 1976) from the Department of Dental Health, University of Adelaide.

The research presented in this thesis focuses on understanding the biomechanical effects of various cranial features that are often ignored in finite element models (FEMs) because their size, position, and complex shapes make them difficult to model. Specifically, this work examines the effects of the alveoli (tooth sockets), periodontal ligament, and squamosal suture on the stress and strain distributions in a cranium under masticatory and dynamic tooth loads. Results from this research will help determine if these features have a significant effect on stress and strain patterns and will yield guidelines as to if or under what conditions they need to be modeled in future FE skull model analyses. As part of this research, three sets of FEMs were developed to address a hypothesis focusing on each cranial feature. The first set of models examined the effect of the tooth sockets on the stress and strain distributions in a cranium under static biting conditions to determine if improperly modeled sockets produce strong global effects in craniofacial regions. The second set of models were used to assess the effect of the PDL's material behavior on the stresses and strains in a cranium under static biting and dynamic tooth loading conditions to determine if the PDL plays an important role in reducing stresses and strains in a model. The final set of models were used to determine the effect of the squamosal suture size on the stresses and strain energies in a cranium under static biting conditions to see if an increase in suture size decreases the risk of separation of the temporal bone from the parietal bone. Results for all analyses indicate the effects of the cranial features are local (i.e. within the vicinity of the feature), with no meaningful global effects. This suggests the sockets, PDL, and squamosal suture do not play an important role in global stress and strain distributions in a cranium under masticatory and dynamic tooth loads. Therefore, it may be safe to ignore the sockets, PDLs, and squamosal sutures during the FE modeling process if the objective of the analysis is to understand global stress and strain patterns.