The 81st Annual Meeting of the American Association of Physical Anthropologists (2012)

Combining occlusal fingerprint analysis and computer-based methods for 3D digital reconstruction of Sts 52


1Department of Anthropology, University of Vienna, 2Department of Palaeoanthropology and Messel Research, Senckenberg Research Institute – Frankfurt, 3Dental Workshop Bensheim, Private Laboratory for Training, Research and Methods – Bensheim

Thursday 10:45-11:00, Grand Ballroom II Add to calendar

The Australopithecus africanus specimen Sts52 includes a partial lower face (Sts52a) and a fragmented mandible (Sts52b). Various defects characterize both parts, so that any attempt to match upper and lower dentition fails. The left hemimandible completely lacks the ramus, part of the corpus, and shows several broken teeth, whilst in the right hemimandible both the coronoid process and the angle are broken. In the left hemiface the maxilla and nasal bones are compressed laterally and shifted backward.

In this contribution we show how the preserved macrowear pattern of the tooth crowns can be used for the functional reconstruction of Sts52's dental arches, and how the restored dental positions provide fundamental information for the digital reconstruction of the whole mandible and the lower face.

High-resolution epoxy casts of the upper and lower dentition were used to extract information of individual antagonistic occlusal contacts. A detailed wear pattern mapping and its functional interpretation constrains the individual crown position and their antagonistic relationship. The reconstructed dental arches were 3D surface scanned, and registered on the 3D models of the original Sts52 specimens. The reconstructed lower dental arch was used to create a target template. Afterwards a reference mandible (Pan troglodytes) was warped onto the target template, restoring the Sts52b mandible. For the Sts52a reconstruction a non-rigid Flow transformation based on scattered data interpolation was performed.

The outcome of this reconstruction shows for the first time a complete functional reconstruction of A. africanus dental arches, thus providing new morphometric data for Sts52.

Supported by National Science Foundation Physical Anthropology HOMINID Grant 2007 (01-120) and by the German Research Foundation (DFG-FOR 771)

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