Enamel microstructure - a truly three-dimensional structure.

Abstract

Paleoanthropological studies often center on teeth, not only because these elements are commonly preserved in the fossil record, but because they apparently contain a wealth of information with regard to development, phylogeny, and function. However, despite a plethora of studies, somefundamental problems are still unresolved. For example, while it is recognized that the 3-dimensional arrangement of enamel prisms may hold important information with regard to phylogeny (von Koenigswald and Sander, 1997) and function (Rensberger, 2000), many paleoanthropological studies have thus far relied on investigating enamel microanatomy as a 2-dimensional structure (e.g., Dean et al., 2001 C Dean, M.G Leakey, D Reid, F Schrenk, G.T Schwartz, C Stringer and A Walker, Growth processes in teeth distinguish modern humans from Homo erectus an earlier hominins, Nature 414 (2001), pp. 628¿631. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (120)Dean et al., 2001). This is mainly due to difficulties in visualizing and quantifying the 3-D structure of prisms. In order to overcome these limitations a computer model was developed (Jiang et al., 2003) which attempted to simulate the effects of biophysical processes governing enamel formation in modern humans (adapted from Osborn, 1970). Here we extend our model and present preliminary data on inter-specific variation in prism arrangement among primates. Furthermore, during our work torecreate the 3D microstructure of prismatic enamel it became increasingly clear that there are not only limitations with previous dental growth studies, but that these studies are based on fundamentally different concepts regarding evolutionary processes from those assumed in our approach. These limitations and differences will be highlighted also.