title: Enamel thickness variation of deciduous first and second upper molars in modern humans and Neanderthals.
abstract: Enamel thickness and dental tissue proportions have been recognized as effective taxonomic discriminators between Neanderthal and modern humans teeth. However, most of the research on this topic focused on permanent teeth, and little information is available for the deciduous dentition. Moreover, although worn teeth are more frequently found than unworn teeth, published data for worn teeth are scarce and methods for the assessment of their enamel thickness need to be developed. Here, we addressed this issue by studying the 2D average enamel thickness (AET) and 2D relative enamel thickness (RET) of Neanderthal and modern humans unworn to moderately worn upper first deciduous molars (dm(1)s) and upper second deciduous molars (dm(2)s). In particular, we used 3D μCT data to investigate the mesial section for dm(1)s and both mesial and buccal sections for dm(2)s. Our results confirmed previous findings of an Neanderthal derived condition of thin enamel, and thinner enamel in dm(1)s than dm(2)s in both Neanderthal and modern humans. We demonstrated that the Neanderthal 2D RET indices are significantly lower than those of modern humans at similar wear stages in both dm(1)s and dm(2)s (p < 0.05). The discriminant analysis showed that using 2D RET from dm(1) and dm(2) sections at different wear stages up to 93% of the individuals are correctly classified. Moreover, we showed that the dm(2) buccal sections, although non-conventionally used, might have an advantage on mesial sections since they distinguish as well as mesial sections but tend to be less worn. Therefore, the 2D analysis of enamel thickness is suggested as a means for taxonomic discrimination between modern humans and Neanderthal unworn to moderately worn upper deciduous molars.
authors.affiliation: Department of Anthropology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. Electronic address: cinzia.fornai@univie.ac.at.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Fornai
authors.affiliation: Department of Cultural Heritage, University of Bologna, Via degli Ariani 1, 48121 Ravenna, Italy; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.
authors.forename: Stefano
authors.initials: S
authors.lastname: Benazzi
authors.affiliation: Institute of Archaeology, Academy of Sciences of the Czech Republic, Královopolská 147, 612 00 Brno, Czech Republic; Department of Anthropology, Faculty of Science, Masaryk University, Vinařská 5, 603 00 Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Svoboda
authors.affiliation: Department of Anthropology, Hungarian Natural History Museum, Ludovika tér 2-6, 1083 Budapest, Hungary.
authors.forename: Ildikó
authors.initials: I
authors.lastname: Pap
authors.affiliation: Paleoanthropology, Senckenberg Center for Human Evolution and Paleoenvironments, Eberhard Karls Universität Tübingen, Rümelnstrasse 23, Tübingen 72070, Germany.
authors.forename: Katerina
authors.initials: K
authors.lastname: Harvati
authors.affiliation: Department of Anthropology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
authors.forename: Gerhard W
authors.initials: GW
authors.lastname: Weber
mesh_terms: D000818:Animals; D003743:Dental Enamel / Q000000981:diagnostic imaging*; D005580:Fossils / Q000000981:diagnostic imaging; D006801:Humans; D008963:Molar / Q000000981:diagnostic imaging*; D059125:Neanderthals; D057085:Tooth Wear / Q000000981:diagnostic imaging; D014094:Tooth, Deciduous / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography
keywords: Deciduous dentition; Dental tissue proportions; Homo neanderthalensis; Homo sapiens; Pleistocene; Tooth wear