Dental Hard Tissue Lab

Histological Preparation and Analysis Facilities

Facilities are available for the generation of high resolution molds and casts, histological thin sectioning of hard tissues, and high resolution imaging using stereo microscopy, polarized light microscopy, and tandem scanning reflected light (confocal) microscopy. Scanning and transmission electron microscopy, and high resolution tomographic imaging are performed at the Harvard University Center for Nanoscale Systems. Synchrotron imaging is performed at the European Synchrotron Radiation Facility through a collaboration with Dr. Paul Tafforeau. High resolution data analysis (virtual histology) is performed in our virtual paleoanthropology laboratory, which is shared with the Skeletal Biology Laboratory. More information on histological thin sectioning may be found here.

Dental Microstructure Studies

Dental development in humans and great apes begins prior to birth and continues throughout adolescence. Like many biological systems, hard tissue formation is characterized by a circadian rhythm. Developmental rate and time are permanently recorded by incremental lines in enamel and dentine, which remain unchanged in these tissues for millions of years. Given that dental remains are the most common, well-preserved type of fossil evidence for extinct species of primates, examination of incremental growth processes may shed new light on the evolutionary developmental biology of early humans.

Examination of hard tissue development from a histological perspective is a relatively new field of odontological inquiry. Recently, there has been a dramatic increase in the number of studies on incremental dental development in hominoids. Studies on Plio-Pleistocene hominids and Neanderthals have indicated that the relatively slow developmental rate and prolonged duration of modern human crown formation may be a fairly recent and unique development.

Histological analysis of dental material facilitates understanding of the final functional products of the processes of development and growth, which may be understood in terms of enamel thickness (macrostructure) and enamel microstructure. Recent studies have provided information on age at death in hominins with developing dentitions, absolute and relative timing of dental development, age at M1 emergence, and differences in the developmental pathways of enamel formation. These studies have important implications for our understanding of hominin evolution and the origin of developmentally modern humans.