Expression of dental traits at the enamel-dentine junction (EDJ). Using microCT scanning the manifestation of dental traits, such as a sixth cusp on lower molars, can be imaged at both the outer enamel surface (left) and EDJ (right). Examining the shape of these traits at the EDJ can improve our understanding of how they grow during the development of the tooth and can indicate the presence of such traits on partially worn teeth. Such traits are used to assess evolutionary relationships among living and fossil primates (including modern humans).
Geometric morphometric analysis of tooth shape. Geometric morphometrics is a landmark-based method of shape analysis that is used to compare the complex morphology of bones and teeth. With Dr. Philipp Gunz, the goal of this project is to apply this method of shape analysis to the enamel-dentine junction of molar teeth. Using this method the complex morphology of the EDJ can be compared between living and fossil species in order to make inferences about their evolutionary relationships. One important advantage of analyzing the EDJ in this way is that it will allow the comparison of tooth shape in partially worn fossil teeth.
Developmental origin of tooth crown shape using Dental Topographic Analysis (DTA). Using GIS software the complex morphology of tooth crowns can be measured as one might measure the topography of a landscape. By measuring the surface aspect (colour-coded above into the four cardinal directions) this component of tooth morphology can be compared at the EDJ (left) and the outer enamel surface (right). Results to date indicate that the EDJ, whose shape is established early in development, contributes significantly to this component of tooth crown shape.