1School of Dental Sciences, Newcastle University, 2Anthropology, University College London, 3Cell and Developmental Biology, University College London
Saturday All day, Park Concourse
Developmental atlases of the great ape and human dentitions have proved invaluable in ontogenetic studies of both cranial and postcranial traits because they allow specimens to be individually aged rather than aggregated into discrete categories. The creation of a similar atlas for the hylobatid dentition allows for extending these comparative ontogentic studies across the hominoid clade. The goal of our preliminary study is to document and provide a chronological time scale for the developing dentition of Hylobates lar using a combination of cross-sectional radiographic data of 18 juvenile gibbon mandibles and histological sections of three lower molars (M1, M2 and M3) from individuals with histologically dervied ages at death (AS1627, NYU008 and NYU029). An atlas of dental formation was created using the radiographic images, with 10 separate stages of tooth mineralization being identifiable across all individuals (based on Dean and Wood's atlas method). Growth increments in the crown and root of histological sections of each molar were used to determine the age for each of the 10 stages. These provided a time-scale of postnatal dental development spanning from 0.22 years (M1 1/4 complete) to 5.8 years (M3 root 1/2 complete). In combination, these data allowed for assigning approximate relative dental ages (ARDA) to each individual gibbon specimen in a way that is comparable to Dean and Wood's great ape atlas. Future work will include histological data for the remaining mandibular dentition (I1, I2, C, P3 and P4), thus increasing the resolution of the method.
Funded by NSF (SBR-9700822) and the Royal Society.