Enamel thickness variation of deciduous first and second upper molars in modern humans and Neanderthals

Cinzia Fornai, Stefano Benazzi, Jiri Svoboda, Ildiko Pap, Katerina Harvati, Gerhard Weber

Publications: Contribution to journalArticlePeer Reviewed

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 1s) and upper second deciduous molars (dm 2s). In particular, we used 3D μCT data to investigate the mesial section for dm 1s and both mesial and buccal sections for dm 2s. Our results confirmed previous findings of an Neanderthal derived condition of thin enamel, and thinner enamel in dm 1s than dm 2s 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 1s and dm 2s (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.

Original languageEnglish
Pages (from-to)83-91
Number of pages9
JournalJournal of Human Evolution
Volume76
Issue numberC
DOIs
Publication statusPublished - 2014

Austrian Fields of Science 2012

  • 106018 Human biology
  • 106012 Evolutionary research

Keywords

  • Dental tissue proportions
  • Tooth wear
  • Deciduous dentition
  • Homo neanderthalensis
  • Homo sapiens
  • Pleistocene

Cite this