Dental conditions and nutrition among natives in Greenland☆

Neanderthal diet has been on the spotlight of paleoanthropological research for many years. The majority of studies that tried to reconstruct the diet of Neanderthals were based on the analysis of zooarchaeological remains, stable isotopes, dental calculus and dental microwear patterns. In the past few years, there have been a few studies that linked dental macrowear patterns of Neanderthals and modern humans to diet and cultural habits. However, they mostly focused on maxillary molars. Although mandibular molars have been widely used in microwear dietary research, little is known about their usage at the macroscopic scale to detect information about human subsistence strategies. In this study, we compare the macrowear patterns of Neanderthal (NEA), fossil Homo sapiens (FHS), modern hunter-gatherers (MHG), pastoralists, early farmers and Australian Aborigines from Yuendumu mandibular molars in order to assess their utility in collecting any possible information about dietary and cultural habits among diverse human groups. We use the occlusal fingerprint analysis method, a quantitative digital approach that has been successfully employed to reconstruct the diet of living non-human primates and past human populations. Our results show macrowear pattern differences between meat-eater MHG and EF groups. Moreover, while we did not find eco-geographical differences in the macrowear patterns of the fossil sample, we found statistically significant differences between NEA and FHS inhabiting steppe/coniferous forest. This latter result could be associated with the use of distinct technological complexes in these two species, which ultimately could have allowed modern humans to exploit natural resources in a different way compared to NEA.

Neanderthals have been traditionally described to be at the very top of the food chain, with a diet consisting almost exclusively of meat. On the other hand, anatomically modern humans (AMH) are thought to be a more flexible species with the exploitation of various food sources. Here we analyze dental macrowear of a large sample of Neanderthal and AMH postcanine teeth from different chronological and geographical areas of Europe and the Near East, applying a well-established method called occlusal fingerprint analysis (OFA). This digital approach is based on the identification and analysis of attrition and abrasive occlusal wear facets (defined as polished homologous areas with well-defined borders) with the aim to reconstruct the jaw movements responsible for their formation. Thus, it enables to obtain information on dietary and non-dietary habits of these populations. Wear facet size and distribution seem to correlate well with diet, showing a large variation within Neanderthals and AMH, which mostly depends on the habitats they inhabited. We found ecomorphological signals distinguishing populations who lived in cold habitats from those who inhabited warm climatic conditions, suggesting an increase in meat consumption at the northern latitudes. In contrast, wear facet inclination is strongly influenced by the environmental abrasiveness accidentally introduced in the mouth through food preparation methods. In addition, we have also identified non-dietary wear on the postcanine dentition in Mediterranean populations that suggests the use of teeth as tools for daily task activities.

This paper describes a quantitative approach to the assessment of dental calculus in human archaeological skeletal samples. The approach combines the ranked calculus scoring method described by Buikstra and Ubelaker [1994. Arkansas Archeological Survey Research Series, Arkansas Archeological Survey, Fayetteville, Arkansas] and a modified Simplified Calculus Index, utilized by dental clinicians. We recorded amounts of calculus on the buccal, lingual, and interproximal surface of all extant teeth, and generated an index for the maxillary posterior dentition, maxillary anterior dentition, mandibular posterior dentition, and mandibular anterior dentition for three skeletal samples. They include 145 Egyptian Predynastic individuals from the site of Hierakonpolis, 104 Predynastic individuals from Naqada, Egypt, and 101 Meroitic Nubians from Semna South, present-day Sudan. Mann–Whitney U tests were used to analyze differences between the sexes and among age groups at each site. The results demonstrate that the calculus indices more effectively reveal trends and differences in calculus severity than frequency data can alone. For example, at Hierakonpolis, males (18–35 years) had significantly more calculus in the maxillary posterior dentition than females, while females (50+ years) had significantly more calculus in the maxillary posterior teeth. Frequency data merely showed that 94% of both males and females had calculus. The use of calculus indices can reveal how quickly calculus accumulates with age within the dental arcade and within a sample. Moreover, better understanding of the severity and location of calculus can improve a researcher's knowledge regarding the effect of calculus on dental pathologies, such as carious lesions and periodontal disease.

A study was conducted on the dentitions of 100 Eskimo children from the Kotzebue, Alaska, area. In spite of periodic dental care provided by the United States Public Health Service, these children continue to lose teeth at an alarming rate as a result of the high incidence of caries. This condition has been shown to be caused by the change from a primitive diet of meat and fat to one which incorporates the starches and refined sugars introduced by the white man. Although the diet has changed, the lack of oral hygiene found in the primitive Eskimo is still lacking in his modern counterpart.

The rampant decay and premature loss of teeth resulting from the change in diet have also caused the incidence of malocclusion to rise dramatically. Although previous studies of primitive Eskimos have reported practically no malocclusion, 82 per cent of the children in this study had malocclusions. The incidence of Class I malocclusions is quite high, indicating the hereditary nature of this jaw relationship in the Eskimo. A few Class II and Class III malocclusions were also noted. Crowding, especially of the anterior teeth, was a common finding with these malocclusions. Cross-bites and edge-to-edge bites of the anterior teeth were also commonly noted.

Maxillary intercanine and intermolar width measurements were in the same range for those with normal occlusions and those with malocclusions. The predominance of the Class I jaw relationships and the constancy of the transverse palatal measurements contradict an earlier report⁶ that degeneration of the middle and lower face is a main contributor to malocclusion in the Eskimo. Apparently, the change in diet has had little effect upon the jaw relationships.

Nearly half of the children in the sample indicated that they were bothered by either the appearance or the functioning of their teeth. This indicates at least some concern for their teeth on the part of these children. Better dental education and oral hygiene would greatly reduce the incidence of caries which, in turn, would reduce the incidence of malocclusion. To improve oral hygiene, a mandatory brushing program mediated by the native schools has been suggested.