From the mouths of babes: Dental caries in infants and children and the intensification of agriculture in mainland Southeast Asia

High prevalence of adult and nonadult scurvy in an early agricultural transition site from Mainland Southeast Asia was associated with decreased survivorship

OBJECTIVES

The osteological paradox recognizes that the presence of lesions is not always directly related with increased mortality. When combined with the clinical, historical, and epidemiological literature on scurvy, survivorship analysis, a form of statistical analysis to assess the relationship between the presence of diseases in the archeological record and survival, helps determine the overall burden of the disease both in terms of morbidity and mortality. This article explores the relationship between scurvy and survivorship in 26 adults from Man Bac, a Neolithic site from northern Vietnam together with prepublished evidence of scurvy in the nonadult population (n = 44).

METHODS

Diagnosis of scurvy included differential diagnosis combined with the Snoddy, A. M. E., Buckley, H. R., Elliott, G. E., Standen, V. G., Arriaza, B. T., & Halcrow, S. E. (2018). Macroscopic features of scurvy in human skeletal remains: A literature synthesis and diagnostic guide. American Journal of Physical Anthropology, 167(4), 876-895. https://doi.org/10.1002/ajpa.23699 threshold criteria and the Brickley, M. B., & Morgan, B. (2023). Assessing diagnostic certainty for scurvy and rickets in human skeletal remains. American Journal of Biological Anthropology, 181, 637-645 diagnostic certainty approaches. Kaplan-Meier survival curves were produced to assess the relationship between the presence of probable scurvy and age-at-death.

RESULTS

The prevalence of probable scurvy in adults (35%) was considerably lower than reported for the nonadults (80%). Almost all lesions observed in the adults were in a mixed stage of healing. Kaplan-Meier analysis demonstrated no difference in survivorship between infants and children (<15 years) with or without probable scurvy, whereas a meaningful difference was observed for the adults and adolescents (15+ years).

CONCLUSIONS

The findings demonstrate that scurvy considerably decreased survivorship to older age categories. The degree of lesion remodeling, however, indicates that scurvy was not necessarily the direct cause of death but contributed to an overall disease burden that was ultimately fatal.

Mandibular morphology and the Mesolithic-Neolithic transition in Westernmost Iberia

Neolithic farming and animal husbandry were first developed in the Near East ~ 10,000 BCE and expanded westwards, reaching westernmost Iberia no later than 5500 BCE. It resulted in major social, cultural, economic and dietary changes. Yet, the impact of this change on human mandibular morphology in Iberia is yet to be assessed, which is regrettable because mandible form is impacted by population history and diet. In this study we used Mesolithic to Chalcolithic Iberian samples to examine the impact of this transition on mandibular morphology. We also compared these samples with a Southern Levantine Chalcolithic population to assess their relationship. Lastly, we assessed dental wear to determine if the morphological differences identified were related to the material properties of the diet. We found differences between samples in mandibular shape but not size, which we attribute to contrasting population histories between Mesolithic and later populations. Some differences in the severity of dental wear were also found between Mesolithic and later Iberian samples, and smaller between the Mesolithic Iberians and southern Levantines. Little relationship was found between wear magnitude and mandibular shape. Altogether, our results show that the Mesolithic-Neolithic Iberian transition resulted in a meaningful change in mandibular morphology, which was likely driven more by population history than by dietary change.

Reproductive life histories influence cariogenesis: Exploring sex-specific variation in dental caries and survivorship in the human past

OBJECTIVES

Differences in dental caries prevalence between males and females is considered a reflection of diet. However, recent syntheses argue that sex-specific variation in dental caries prevalence also reflects changes in the oral cavity attributable to variation in reproductive life histories. This study explores sex-specific variation in carious lesions using a life history perspective to understand if differences in reproductive ecology influence this process.

MATERIALS AND METHODS

Survival probability between 860 males and females from the Terry Collection was compared using carious lesion manifestation (absent, crown presence, root/cemento-enamel junction [CEJ] presence) and sex as covariates and age as a time series variable. A four-way multivariate analysis of variance (MANOVA) comparing carious lesion type by sex, age, and periodontal disease presence was used to evaluate interaction between these variables.

RESULTS

Individuals with carious lesions have greater survivorship than those without lesions. Males and females with crown lesions do not differ in survivorship from individuals without carious lesions. Females with root/CEJ lesions are characterized by the highest survivorship. A significant interaction was found for root/CEJ carious lesions by age, sex, and periodontal disease presence. Root/CEJ lesion formation in older males was not dependent upon periodontal disease presence, though dependence between these variables characterizes postmenopausal females.

CONCLUSION

Sex-specific variation in crown lesions is not associated with reproductive life histories and likely reflects diet. By contrast, root/CEJ lesions form through pathways attributable to reproductive life histories, particularly age-induced periodontal disease in females. These results suggest the formation of carious lesions is complex, and in some cases, rooted in reproductive life histories.

Stable isotope and dental caries data reveal abrupt changes in subsistence economy in ancient China in response to global climate change

Prior to the introduction of wheat and barley from Central Asia during the Neolithic period, northern Chinese agricultural groups subsisted heavily on millet. Despite being the focus of many decades of intensive interest and research, the exact route(s), date(s), and mechanisms of the spread and adoption of wheat and barley into the existing well-established millet-based diet in northern China are still debated. As the majority of the important introduced crops are C₃ plants, while the indigenous millet is C₄, archaeologists can effectively identify the consumption of any introduced crops using stable carbon isotope analysis. Here we examine published stable isotope and dental caries data of human skeletal remains from 77 archaeological sites across northern and northwestern China. These sites date between 9000 to 1750 BP, encompassing the period from the beginning of agriculture to wheat’s emergence as a staple crop in northern China. The aim of this study is to evaluate the implications of the spread and adoption of these crops in ancient China. Detailed analysis of human bone collagen δ¹³C values reveals an almost concurrent shift from a C₄-based to a mixed C₃/ C₄– based subsistence economy across all regions at around 4500–4000 BP. This coincided with a global climatic event, Holocene Event 3 at 4200 BP, suggesting that the sudden change in subsistence economy across northern and northwestern China was likely related to climate change. Moreover, the substantially increased prevalence of dental caries from pre–to post–4000 BP indicates an increase in the consumption of cariogenic cereals during the later period. The results from this study have significant implications for understanding how the adoption of a staple crop can be indicative of large-scale environmental and socio-political changes in a region.

Caries, antemortem tooth loss and tooth wear observed in indigenous peoples and Russian settlers of 16th to 19th century West Siberia

OBJECTIVE

Increased prevalence of dental caries evidently is correlated with increasing intake of sugar and carbohydrate-rich foods. Preceding and accompanying this dietary alteration might have been a shift from a hunting-and-gathering subsistence strategy to one based on agriculture. We corroborated this conjecture by means of a study on the prevalence of caries, antemortem tooth loss (AMTL) and tooth wear among 16th to 19th century hunter-gatherers and agriculturalists who co-existed in West Siberia.

DESIGN

Indigenous skeletons (n = 75) exhumed from Tatar, Selkup, Khant, and Nenet graves along with Russian settler skeletons (n = 79) from Izyuk were examined. The prevalence of caries, AMTL and tooth wear among the indigenous peoples were compared with those among the Russian settlers. The resulting statistical inferences were tested using package R.

RESULTS

The agriculturalist Russian settlers showed a significantly higher prevalence of dental caries (11.88%) than did the non-agriculturalist indigenous Siberian people (3.85%). Among the latter, the prevalence was the lowest in the Khanty and the highest in the Tatars, suggesting that caries differently affected each sub-group of indigenous Siberian people. Correspondingly to the case of dental caries, the Russian settlers' AMTL prevalence also was higher than that of the indigenous Siberians, regardless of age. On the other hand, the native Siberians and the Russian settlers did not show statistical differences in tooth wear.

CONCLUSION

In the study on 16th to 19th century West Siberian populations, we were able to corroborate our presumption that agriculturalists ingesting a carbohydrate-rich diet would have higher rates of dental caries and AMTL than would hunter-gatherers.

Frequency of dental caries in children in the Early Iron Age and the Medieval populations from Ukraine

In this paper we determine the caries frequency in children of the Early Iron Age (EIA) (the 9th - the 3d centuries BC) and the Medieval populations (the 8th - the beginning of the 15th century AD) from the Ukraine area, and compare the results with the data from several European populations who lived at the same time. The EIA is presented by 41 children skeletons, three of which were Cimmerian (the 9th - the 7th centuries BC) from the territory of contemporary Poltava region; 38 skulls from the territory of contemporary Poltava region and Crimea represented Scythian period (the 7th - the 3d centuries BC). Remains of 24 children from the Medieval populations were also examined, three of which were the ancient Hungarians from the Poltava region (the 8th - the 9th centuries AD), 6 Khazars from the Kharkiv region (the 8th - the 9th centuries), 1 child related the Old Rus culture from the Kyiv region (the 9th century), and 14 representatives of the nomadic populations in the Golden Horde period (the 13th - the beginning of the 15th century) from the Poltava and Zaporizhzhya regions. Taking in consideration the letter archaeobotanical studies we suggest that there were no major changes in the plants exploited during all the studied periods. The frequency of carious lesions in children from the Medieval populations (8.3% in individuals, 0.5% in deciduous teeth, and 0.4% in permanent teeth) is only slightly higher than those from the EIA period (2.4% in individuals and 0.2% in deciduous teeth). These indexes were not larger those of majority of European populations dated to the same historic period. Further isotopic, chemical and palaeobotanical studies of the additional sites, with sufficient sample sizes, allow us to learn so much more of the cariogenic factors in children of the past populations from the Ukraine area.

Molecular analysis of ancient caries

An 84 base pair sequence of the Streptococcus mutans virulence factor, known as dextranase, has been obtained from 10 individuals from the Bronze Age to the Modern Era in Europe and from before and after the colonization in America. Modern samples show four polymorphic sites that have not been found in the ancient samples studied so far. The nucleotide and haplotype diversity of this region have increased over time, which could be reflecting the footprint of a population expansion. While this segment has apparently evolved according to neutral evolution, we have been able to detect one site that is under positive selection pressure both in present and past populations. This study is a first step to study the evolution of this microorganism, analysed using direct evidence obtained from ancient remains.