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


Anterior tooth root morphology in Neanderthals and anatomically modern humans: quantification and functional implications

ADELINE LE CABEC1,2, KORNELIUS KUPCZIK1, JOSÉ BRAGA2 and JEAN-JACQUES HUBLIN1.

1Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany, 2UMR 5288 CNRS, Anthropobiologie et Imagerie Anatomique, Université Paul Sabatier, Toulouse, France

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Neanderthals incisors and canines have been described as long-rooted and this has been used to taxonomically differentiate Neanderthals from modern humans (MH). The anterior dental loading hypothesis (ADLH) explains this difference as an adaptive response in Neanderthals to higher or more frequent loads on the anterior dentition.

This research tests whether a broader set of anterior root dimensions (length, surface area, total volume, pulp volume and cervical area) can distinguish Neanderthals from MH. We used high resolution micro-computed tomography (~27µm) to access the root morphology of in situ and isolated teeth, and internal dental tissue proportions. Our samples comprise maxillary and mandibular permanent incisors and canines from Neanderthals (N=96), recent MH (N=152) and early MH (EAMH, N= 9). Isolated specimens were also included in the analysis: Mauer (Middle Pleistocene), Oberkassel (Magdalenian) and Combe-Capelle (Mesolithic). Mann-Whitney-U tests performed on the root variables indicate that Neanderthals display significantly larger values than recent MH for all the measured parameters in anterior dentition (p<0.01). Mauer falls close to the means of the Neanderthals and EAMH within the lower range of the Neanderthal variation. Our results demonstrate the strength of these metrics to distinguish Neanderthals from recent modern humans. However, the distributions of the two groups overlap and taxonomic attribution of isolated teeth cannot be based solely on root metrics. The ADHL hypothesis cannot be rejected and the larger root surface areas in Neanderthals may have been an adaptation to high loads on the anterior dentition.

This research was supported by the Max Planck Society and the EVAN Marie Curie Research Training Network MRTN-CT-019564.

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