Littérature scientifique sur le sujet « Paleoanthropology, Dental Anthropology, Human dental tissues, Human Evolution »

Dental anthropology has been developed for 100 years in China. In this paper, the author reviews the articles on dental anthropology related to Chinese materials in the past one hundred years and briefly introduces the issues involved such as human evolution, and the interaction of different populations in historical periods. Results and discussion. The work of foreign scholars has been the foundation of Chinese paleoanthropology and dental anthropology since the discovery of the Hetao human teeth and the Zhoukoudian site. Since then, dental anthropology in China has gone through a phase of material accumulation, a phase of introducing the American ASUDAS in the 1990s, and a phase of prosperity in the last 30 years. The numerous discoveries and the application of new techniques have brought Chinese dental anthropology to an international level. Until now, there are more than 70 human fossil sites in China, over 60 of which contain human dental remains. Less material has been found from the early Pleistocene, and there is some controversy on whether they belong to the genus Homo. While early Middle Pleistocene Homo erectus teeth show primitiveness and some special features, the late Middle Pleistocene human teeth show greater variability, and mosaic features, and there is some controversy on whether some fossils belong to early Homo sapiens or other taxa. The Late Pleistocene human dentition is related to the question of how and when early modern human appeared in China and the evolution of early modern humans. However, due to the incompleteness of the material, the question of human origins is a matter of multidisciplinary and comprehensive interpretation. About 10 sites were studied from Neolithic to modern human dentition using the American ASUDAS. These results show the consistency of non-metric traits in teeth and skulls, display differences between northern and southern Chinese populations, and reveal the exchange between northwestern Chinese and western populations. Some of these results have been confirmed by paleogenomics. Conclusion. Anthropologists began to pay more attention to the morphology of modern human teeth. In the future, the application of new methods and the collection of modern human materials will help us better understand the evolution of ancient humans, population interaction.

In the last two decades, a large number of anthropological papers have been focused on digital copies of pa-laeoanthropological materials rather than original skeletal remains. According to some foreign scholars, “virtual anthropology” has taken a shape of a separate field of anthropological science. One of the main advantages of “virtual anthropology” is the possibility to develop databases, datasets, digital collections and catalogues accessi-ble to the scientific community worldwide. Digitization of research objects facilitates organizational side of studies, provides access to wider data, expands the toolkit of available research methods, and also provides safety to the original materials. At the same time, the variability of types of virtual models along with the absence of generally accepted protocols complicate verification of morphometric and structures data. The main goal of this review pa-per is to structure the available information on virtual palaeoanthropological databases and the materials they contain. 3D-scanning technologies can be generally divided into surface scanning (including photogrammetry) and tomographic scanning. The first group of technologies provide 3D models of the shape of an object, accurate enough to be used in morphometric studies if resolution of the equipment is adequate for the size of the object and aims of the study. The second group is designed to scan the whole form of an object, which allows the ex-amination of its internal structures or tissues, small surface structures or dental material. Both methods have their strengths and weaknesses: while surface scans are cheaper and easier to obtain, CT scans provide information unavailable from the former technique. Assessment of qualitative and quantitative characteristics of digital copies depends on objectives of the study. The article provides an overview of 17 databases of virtual paleoanthro-pological models, which comprise either surface or CT scans, or both. These materials can be used in various fields of study, including human evolution, primatology, palaeoanthropology, palaeopathology, forensic science, human anatomy, as well as in teaching of these subjects. For each collection, approximate number of objects and terms of use have been specified.

The subject of this doctoral dissertation concerns the usefulness of virtual analysis approach in studies of dental tissues and their defects. The real symmetry and perfect balance between opposite jaw halves and antagonistic teeth is not the reality in the masticatory system. The sample of Yuendumu Aboriginal people used in Paper I consists of complete maxillary and mandibular dental arch 3D models from 19 individuals (young and adult). The analysis was carried out on first molars from all quadrants and only individuals with similar levels of wear were selected (76 teeth in total). Virtual methods were applied in order to inspect the palatal arch asymmetries in relation to the alveolar bones inclination and consequently, the alteration of dental crown. Crown alteration (Enamel and Dentine) could be produced by several factors such as masticatory activity, pathological, anthropic and cultural alterations. However, anthropological studies are sometimes not able to distinguish differences among them without an interdisciplinary approach. Particularly, pathological alterations (pits and fissures) are extremely difficult to interpret without microscopy analysis. That is the reason why a virtual approach in dental studies is useful to understand and distinguish any natural or anthropic alteration. Two examples are shown in Paper II and Paper III where two dental treatments discovered in two Italian sites have been described: Villabruna specimen and Fredian shelters. The modern human specimen Villabruna (Paper II) from a burial in Northern Italy is the earliest evidence of dental therapeutic intervention on a Late Upper Paleolithic (ca. 14,000 yr BP). Using Scanning Electron Microscopy (SEM) we showed the presence of striations deriving from the manipulation of a large occlusal carious cavity of the lower right third molar. The striations have a “V’’-shaped transverse section and several parallel micro-scratches at their base, as typically displayed by cutmarks on teeth. Based on in vitro experimental replication and a complete functional reconstruction of the Villabruna dental arches, we confirmed that the identified striations and the associated extensive enamel chipping on the mesial wall of the cavity were produced ante-mortem by pointed flint tools during scratching and chiseling activities. Similar situation was identified at the Fredian shelter (Paper III). The two upper incisors display exposed pulp chambers with circumferential enlargement, chipped dentine on the cavity margins and striations on the cavity walls. Histochemical analysis of the material embedded at the bottom of the cavities revealed a conglomerate of vegetal fibers and probably hairs. Moreover, Fourier transform infrared spectroscopy (FTIR), energy dispersion X-ray spectroscopy (EDS), and Raman microscopy analysis of black residue adhering to the walls of both cavities is consistent with organic substances, specifically bitumen. A direct chronometric date for Fredian 5 confirms a Late Upper Paleolithic context (between 13,000-12,735 calendar years ago). Overall, our results are consistent with in vivo dental drilling to remove necrotic or infected pulp tissue (pulpitis) and the subsequent use of a composite, organic dental filling in the cavity. The conservation of human remains is the main interest of good anthropological research and any organic matter identified within a dental cavity needs to be conserved. This is the topic of paper IV: Letter to the Editor I had written in order to clarify the reason why we have decided to use three different methods (infrared spectroscopy (FTIR), energy dispersion X-ray spectroscopy (EDS), and Raman microscopy analysis) rather than gas-chromatography. Finally, when a tooth does not show any pathological alteration or exhibits a normal/slight wear pattern on the occlusal surface (wear stage 1-2, 3 Smith, 1974) it is possible to obtain information regarding taxonomy based on volume (3D) or areas (2D) of Enamel, Dentine (paper V, VI, VII. VIII) and morphometric analysis of teeth's root (paper IX). This thesis therefore strives to provide a contribution to understanding how virtual approach to dental studies can be used to increase the knowledge of dental tissues and their defects.

Tooth enamel and dentin are the most studied hard tissues used to explore hominin evolution, life history, diet, health, and culture. Surprisingly, cementum (the interface between the alveolar bone and the root dentin) remains the least studied dental tissue even though its unique growth, which is continuous throughout life, has been acknowledged since the 1950s. This interdisciplinary volume presents state-of-the-art studies in cementum analysis and its broad interpretative potential in anthropology. The first section focuses on cementum biology; the second section presents optimized multi-species and standardized protocols to estimate age and season at death precisely. The final section highlights innovative applications in zooarchaeology, paleodemography, bioarchaeology, paleoanthropology, and forensic anthropology, demonstrating how cementochronology can profoundly affect anthropological theories. With a wealth of illustrations of cementum histology and accompanying online resources, this book provides the perfect toolkit for scholars interested in studying past and current human and animal populations.