Dental caries prevalence as evidence for agriculture and subsistence variation during the Yayoi period in prehistoric Japan: biocultural interpretations of an economy in transition

Direct evidence of plant consumption in Neolithic Eastern Sudan from dental calculus analysis

The Neolithic communities of Eastern Sudan combined intensive pastoralism with plant exploitation as their main subsistence strategies. However, to date, it remains unclear which plant species were part of the human diet during the Neolithic. This contribution presents direct data on plant consumption in Eastern Sudan from the Early to Late Neolithic, obtained through the analysis of microdebris inclusions in the dental calculus of 37 individuals, integrated by dentoalveolar pathology analysis of 78 individuals, from the sites UA53 (4th millennium BCE) and Mahal Teglinos (3rd-2nd millennium BCE), located in the Gash Delta/Kassala region. Dental calculus inclusions indicate a diverse intake of cereals, legumes, and tubers during the Middle Neolithic, thus supporting the hypothesis of high reliance on plant resources. Dentoalveolar pathologies, possibly related to the consumption of carbohydrate-rich foods, have also been recorded. For the Late Neolithic, consistent with the shift towards aridity that occurred in the Middle/Late Holocene, dental calculus exclusively indicates the exploitation of sorghum and tubers-species well adapted to arid conditions-showing how the Neolithic communities modified their subsistence in response to environmental changes. Evidence of plant processing techniques, such as cooking/heating, was also revealed from the dental calculus analysis.

Beyond dirty teeth: Integrating dental calculus studies with osteoarchaeological parameters

The study of ancient human dental calculus (mineralized dental plaque, also known as tartar) is becoming increasingly important in osteoarchaeology, human palaeoecology and environmental archaeology. Microremains of different origin (e.g. starch granules, pollen, phytoliths, feather barbules) as well as biomolecules and chemical compounds retrieved from its mineral matrix may represent an important link between past humans and their physical, biological and social environment, but they are rarely fully linked to the evidence from skeletal remains. This paper critically reviews the lines of evidence retrieved from dental calculus in relation to osteoarchaeological parameters, employing macroscopic, microscopic and biomolecular approaches, assessing synergy potential and limitations. The scope of this paper is also to contribute to the building of a much needed theoretical framework in this emerging subfield.

Modern Japanese ancestry-derived variants reveal the formation process of the current Japanese regional gradations

Modern Japanese people have two major ancestral populations: indigenous Jomon hunter-gatherers and continental East Asian farmers. To determine the formation process of the current Japanese population, we developed a detection method for variants derived from ancestral populations using a summary statistic, the ancestry marker index (AMI). We applied AMI to modern Japanese population samples and identified 208,648 single nucleotide polymorphisms (SNPs) that were likely derived from the Jomon people (Jomon-derived variants). Analysis of Jomon-derived variants in 10,842 modern Japanese individuals recruited from all over Japan revealed that the admixture proportions of the Jomon people varied between prefectures, probably owing to the prehistoric population size difference. The estimated allele frequencies of genome-wide SNPs in the ancestral populations of the modern Japanese suggested their adaptive phenotypic characteristics to their respective livelihoods. Based on our findings, we propose a formation model for the genotypic and phenotypic gradations of the current Japanese archipelago populations.

Dental Calculi of Siberian Natives, Russian Settlers, and Korean People of Joseon Dynasty Period in the 16th to 19th Century Eurasia Continent

Objective

The prevalence of calculus is known to be variable by difference in diets or subsistence strategy between human populations. However, this situation has not been confirmed so far for hunter-gatherers and farming people in terms of history. In this study, we tried to reveal the association of diets or subsistence with calculus in different historical populations: Siberian natives, Joseon period Korean people, and Russian settlers in Siberia.

Design

We examined the teeth of Siberian natives (hunter-gatherers), Russian (wheat farming) settlers, and Joseon (rice farming) people in sixteenth to nineteenth century. Age and sex were estimated using the methods of Buikstra and Ubelaker (1994). We examined specimens to detect signs of calculus formation in teeth. Calculus rates in each group were statistically compared, and the proportions of calculus by age or sex were also compared across each group. We used package R for statistical analysis. Results and Discussion. The prevalence of calculus deposition decreased in the order of Joseon people, Russian settlers, and Siberian natives. Our study proposes that the rate of calculi among farming people was evidently higher than that of hunter-gatherers in sixteenth to nineteenth century Eurasia. In all three groups, calculus prevalence became higher as age increases and was noteworthy in males.

Conclusion

Current study demonstrated a significant difference of calculus formation between those groups with different diets or subsistence strategies. Higher prevalence of dental calculus was observed in agriculturalist Joseon Koreans and Russian settlers, but Siberian natives exhibited relatively lower frequency of dental calculus. The results of this study enable us to reconsider the meaning of association between subsistence strategy and calculus in different historical populations.

Oral conditions of the pre-Hispanic mummies of Gran Canaria (Canary Islands, Spain)

OBJECTIVE

To analyse the oral conditions of pre-Hispanic mummies from Gran Canaria (5th-11th centuries AD), comparing the results with published data from the non-mummified population.

MATERIALS

440 teeth and 764 alveoli of 30 adult mummies.

METHODS

Macroscopic examination of pathological and non-pathological features of the oral cavity, using standardized criteria.

RESULTS

The mummies reveal frequent dental caries (11.8%), especially affecting molars (27.6%), a high prevalence of calculus (66.3%) and periodontal disease (34.9%). The average wear is characterized by extensive dentine exposure. Periapical lesions (10.6%) and antemortem tooth loss (AMTL) (15.9%) are common. A high percentage of individuals exhibit linear enamel hypoplasia (LEH) (84%). Except for periodontitis, the data indicate the absence of significant statistical differences between the mummies and the skeletonized sample.

CONCLUSIONS

The profile of the dental pathologies of the mummies indicates a carbohydrate-rich diet that contained abrasive grit from the stone querns used to grind cereals. Comparison of the oral conditions of mummified and skeletonized remains shows no differences in access to food resources, reinforcing the recent rejection of the traditional interpretation of the mummies as the pre-eminent status group of Canarian society.

SIGNIFICANCE

This is the first study to delve into the oral conditions of pre-Hispanic mummified remains from Gran Canaria. The results have implications for the framing of research questions based on the social status of these mummies.

LIMITATION

The preserved sample of mummified remains of ancient Canarians is small.

SUGGESTION FOR FURTHER RESEARCH

Comparative analysis from a diachronic perspective would improve understanding of the historical development of ancient Canarians.

Exploring oral paleopathology in the Central Andes: A review

This targeted review of oral paleopathology in the Central Andes explores research that focuses on a set of interrelated, multifactorial processes: dental caries, macrowear, alveolar abscess, antemortem tooth loss (AMTL), periodontal disease, and the presence of dental calculus. These conditions help characterize oral health because they result from the culturally mediated interaction of individuals' oral cavity with their external environment. To better understand how osteologists working in the Central Andes have interpreted the frequencies of these conditions, I review the etiology of each, as well as discuss the important issues in their analyses. I then highlight studies that integrate of a number of oral paleopathological conditions, that examine associations between oral conditions and other skeletal indicators of health, or that use multivariate statistical techniques to analyze conditions. In the Central Andes, these proxies for oral health have generally focused on several key research themes including the introduction of domesticated foods may have occurred earlier than expected, but that populations may have maintained mixed subsistence strategies for a significant period. Researchers have also identified that changes accompanying Inca imperialism were likely not as detrimental to local populations as was Spanish colonialism. Finally, the long-practiced, culturally important, activity of chewing coca has been shown to create an identifiable pattern of oral paleopathological conditions.

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.

Diet variability among pre-Dogon and early Dogon populations (Mali) from stable isotopes and dental diseases

AIMS AND OBJECTIVES

This article reports on diet variability in the Dogon Country (Mali) through a bio-archeological study of pre-Dogon and early Dogon human remains (7th century to 19th century AD) from collective burial caves in the Bandiagara Escarpment.

MATERIALS AND METHODS

Two hundred and twenty crania from collections curated in Leiden, Paris, and Bamako were studied for dental diseases. In a subset of teeth (n = 175), δ¹³ C and δ¹⁵ N were measured in bulk dentine samples.

RESULTS

δ¹³ C and δ¹⁵ N values vary widely (-15.4 to -6.0‰ for δ¹³ C, 6.0-14.8‰ for δ¹⁵ N, n = 175), and indicate diets dominated by C₄ -based foods with a focus on plants; animal products played a minor role. There are significant differences between the δ¹³ C values from older (pre-Dogon) and younger (Dogon) periods. Frequencies of caries, antemortem tooth loss, and abscesses increase significantly through time. Individuals from northern caves have more positive δ¹³ C and δ¹⁵ N values than southern ones.

DISCUSSION AND CONCLUSIONS

The temporal shifts are probably due to progressive diversification of foods, consistent with archeological evidence showing the addition of rice and vegetables to pearl millet. The geographical disparity is explained by a combination of climatic, environmental, and cultural factors. Last, intersite differences imply that different communities (or subsections thereof) disposed of their dead in different caves. Based on a large sample extending over a wider area and longer time frame than previous work, our study shows that diets in the Dogon Country were neither uniform nor continuous through time, as previously proposed. Our results attest to a complex history of settlement and foodways.

Making sense of medieval mouths: Investigating sex differences of dental pathological lesions in a late medieval Italian community

OBJECTIVES

Bioarchaeological investigations of sex-based differences in the prevalence of dental pathological lesions, particularly caries, have drawn considerable attention, and out of this work, two dominant models have emerged. Traditionally, the first model interprets sex-related patterns in caries as a product of gendered differences in diet. A more recent model interprets a generally higher propensity for caries prevalence in females in light of reproductive ecology. To test the hypothesis that females have higher risk of caries in accordance with reproductive ecology, we examined and analyzed caries prevalence and other potentially synergistic oral pathological lesions in a late medieval (A.D. 1300-1500) Italian archaeological sample.

MATERIALS AND METHODS

We examined sex- and age-related prevalence in caries and other oral pathological lesions in a late medieval Italian skeletal assemblage excavated from Villamagna consisting of 38 females and 37 males (n = 1,534 teeth). We examined age- and sex-related patterns in six dental traits: antemortem tooth loss, caries, calculus, periapical inflammation, tooth wear, and periodontitis.

RESULTS

Significant age-related increases in antemortem tooth loss, caries, calculus, and tooth wear were observed in both males and females. However, there was a lack of expected sex differences in oral pathological lesions, with instead older males exhibiting significantly more antemortem tooth loss and corrected caries than females.

DISCUSSION

Results are discussed in relation to the ethnohistoric context of medieval rural dietary practices as well as biomedical salivary literature, which suggest that dietary changes throughout the life course may have facilitated trade-offs that buffered females from higher rates of dental pathological lesions.

Assessing subsistence and its relationship to cultural complexity in the late prehistoric upper Midwest: A new perspective provided by dental health

OBJECTIVE

Previous researchers have assumed that the Late Prehistoric Oneota were less reliant on maize agriculture than their Middle Mississippian neighbors to the south. This assumption is based on the idea that intensive maize agriculture is related to sociopolitical complexity, and that the climate of the Great Lakes region was less conducive to full-scale agriculture than that of the American Bottom. Here, we assess the diet of the Oneota using dental pathology to test the hypothesis that the Oneota in Eastern Wisconsin were highly reliant on maize agriculture.

MATERIALS AND METHODS

To test our hypothesis, skeletal remains representing 187 individuals and 1,102 teeth were examined from nine Oneota sites from the Middle Fox and Koshkonong Localities, as well as the Late Woodland/Middle Mississippian site of Aztalan. Dental caries, antemortem tooth loss (AMTL), and dental abscesses were assessed for each individual in the sample. Dental pathologies in the Oneota groups were compared to each other based on Locality and to the Aztalan population using chi-squared tests.

RESULTS

Dental caries rates for the Oneota, based on the tooth count approach, were observed at 16.8% for the Middle Fox Locality, and 49% for the Koshkonong Locality. Comparatively, the Late Woodland/Middle Mississippian population from Aztalan had a tooth count rate of 19.5%. AMTL rates were similar across samples. Dental abscessing was universally low.

DISCUSSION

The relatively high rate of dental caries among the Oneota is comparable to Middle Mississippian populations from throughout the Midwest, suggesting similar reliance on maize between the groups.

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.

Spatial variation of dental caries in late holocene samples of Southern South America: A geostatistical study

OBJECTIVE

The spatial variation of dental caries in late Holocene southern South American populations will be analyzed using geostatistical methods. The existence of a continuous geographical pattern of dental caries variation will be tested.

METHODS

The author recorded dental caries in 400 individuals, collated this information with published caries data from 666 additional individuals, and calculated a Caries Index. The caries spatial distribution was evaluated by means of 2D maps and scatterplots. Geostatistical analyses were performed by calculating Moran's I, correlograms and a Procrustes analysis.

RESULTS

There is a relatively strong latitudinal continuous gradient of dental caries variation, especially in the extremes of the distribution. Moreover, the association between dental caries and geography was relatively high (m₁₂  = 0.6). Although northern and southern samples had the highest and lowest frequencies of dental caries, respectively, the central ones had the largest variation and had lower rates of caries than expected.

CONCLUSION

The large variation in frequencies of dental caries in populations located in the center of the distribution could be explained by their subsistence strategies, characterized either by the consumption of wild cariogenic plants or cultigens (obtained locally or by exchange), a reliance on fishing, or the incorporation of plants rich in starch rather than carbohydrates. It is suggested that dental caries must be considered a multifactorial disease which results from the interaction of cultural practices and environmental factors. This can change how we understand subsistence strategies as well as how we interpret dental caries rates. Am. J. Hum. Biol., 2016. © 2016 Wiley Periodicals, Inc. Am. J. Hum. Biol. 28:825-836, 2016. © 2016Wiley Periodicals, Inc.

Sex differentials in caries frequencies in Medieval London

OBJECTIVE

Tooth decay is one of the most common oral infections observed in skeletal assemblages. Sex differentials in caries frequency are commonly examined, with most studies finding that females tend to have a higher frequency of carious lesions (caries) compared to males. Less research has examined differences in caries between males and females with respect to age in past populations. Findings from living populations indicate that caries frequencies are higher in females, at least in part, because of the effects of estrogen and pregnancy. We are interested in the interaction of age, sex, and caries in medieval London, during a period of repeated famines, which might have exacerbated underlying biological causes of caries sex differentials.

DESIGN

We examined caries in adults from two medieval London cemeteries dating to c. 1120-1539 AD: St. Mary Spital (n=291) and St. Mary Graces (n=80) to test the hypothesis that males and females have different caries frequencies irrespective of age. The association between maxillary molar caries and sex was tested using hierarchical log-linear analysis to control for the effects of age on caries frequencies.

RESULTS

The results indicate a higher frequency of maxillary molar caries in females (P<0.00), and that the age distribution of caries differs between the sexes (P=0.01), with a consistent increase in frequency with age for females until late adulthood, but not males.

CONCLUSIONS

The difference in caries frequencies is not explained by differences in the age distributions of the sexes. Differences in the age patterns of caries for males and females could be the result of biological factors that present during reproductive age, differences in diet, or differential access to resources during famine.

Review of nanomaterials in dentistry: interactions with the oral microenvironment, clinical applications, hazards, and benefits

Interest in the use of engineered nanomaterials (ENMs) as either nanomedicines or dental materials/devices in clinical dentistry is growing. This review aims to detail the ultrafine structure, chemical composition, and reactivity of dental tissues in the context of interactions with ENMs, including the saliva, pellicle layer, and oral biofilm; then describes the applications of ENMs in dentistry in context with beneficial clinical outcomes versus potential risks. The flow rate and quality of saliva are likely to influence the behavior of ENMs in the oral cavity, but how the protein corona formed on the ENMs will alter bioavailability, or interact with the structure and proteins of the pellicle layer, as well as microbes in the biofilm, remains unclear. The tooth enamel is a dense crystalline structure that is likely to act as a barrier to ENM penetration, but underlying dentinal tubules are not. Consequently, ENMs may be used to strengthen dentine or regenerate pulp tissue. ENMs have dental applications as antibacterials for infection control, as nanofillers to improve the mechanical and bioactive properties of restoration materials, and as novel coatings on dental implants. Dentifrices and some related personal care products are already available for oral health applications. Overall, the clinical benefits generally outweigh the hazards of using ENMs in the oral cavity, and the latter should not prevent the responsible innovation of nanotechnology in dentistry. However, the clinical safety regulations for dental materials have not been specifically updated for ENMs, and some guidance on occupational health for practitioners is also needed. Knowledge gaps for future research include the formation of protein corona in the oral cavity, ENM diffusion through clinically relevant biofilms, and mechanistic investigations on how ENMs strengthen the tooth structure.

The contribution of natural selection to present-day susceptibility to chronic inflammatory and autoimmune disease

Chronic inflammatory and autoimmune diseases have been the focus of many genome-wide association studies (GWAS) because they represent a significant cause of illness and morbidity, and many are heritable. Almost a decade of GWAS studies suggests that the pathological inflammation associated with these diseases is controlled by a limited number of networked immune system genes. Chronic inflammatory and autoimmune diseases are enigmatic from an evolutionary perspective because they exert a negative affect on reproductive fitness. The persistence of these conditions may be partially explained by the important roles the implicated immune genes play in pathogen defense and other functions thought to be under strong natural selection in humans. The evolutionary reasons for chronic inflammatory and autoimmune disease persistence and uneven distribution across populations are the focus of this review.

The prevalence and distribution of dental caries in four early medieval non-adult populations of different socioeconomic status from Central Europe

OBJECTIVES

The aim of the study was to map the dental health status in non-adult individuals and to verify whether and how the existence of caries in the non-adult age group is associated with the different socio-economic status of early medieval populations.

MATERIAL AND METHODS

We studied the dental remains from the acropolis of the Mikulčice settlement agglomeration, where members of the higher social classes were buried, and from the Mikulčice hinterland. Overall, we evaluated 2544 teeth/3714 alveoli of deciduous dentition and 1938 teeth/2128 alveoli of permanent dentition. We determined the number of individuals with dental caries (i.e., caries frequency index, F-CE) and the proportion of teeth/alveoli with caries/ante-mortem tooth loss (i.e., caries intensity index, I-CE).

RESULTS

We found no statistical significant difference in the F-CE values between the Mikulčice hinterland and the acropolis. In addition, we found no statistically significant difference in the proportion of teeth with carious lesions (I-CE) either in the case of deciduous dentition or in the case of permanent dentition between the hinterland and the acropolis. In the case of permanent dentition, the statistically significant highest proportion of carious lesions (I-CE) was found in Mikulčice I (p ≤ 0.05). We confirmed an increase in the rate of caries with age.

CONCLUSIONS

The level of caries at all of the studied medieval locations was very low. We presume that lifestyle and the associated dietary habits and hygienic practices of the individuals or population groups had a greater influence on dental caries than did the socio-economic status of these individuals.

A comparison of female and male oral health in skeletal populations from late Roman Britain: implications for diet

OBJECTIVES

Textual sources from the Roman period point to the existence of dietary differences between the sexes. The aim of this study was to assess the palaeopathological evidence for such gender differences in dietary habits in Roman Britain by comparing the oral health of sexed individuals from two late Romano-British sites (Ancaster, Lincolnshire, and Winchester, Hampshire, England).

MATERIALS AND METHODS

Eighty-seven females (1243 teeth and 1950 sockets) and 112 males (1984 teeth and 2903 sockets) were examined for the presence of five dento-alveolar conditions, namely caries, calculus, periapical lesions, periodontal disease, and antemortem tooth loss. The frequency of each condition was calculated at the per individual and per tooth/socket level, and the results were compared between the sexes using Fisher's exact tests.

RESULTS

Caries and antemortem tooth loss were slightly more common among women, but differences between the sexes were generally not significant. Males experienced higher rates of calculus and periodontal disease. There were no sex differences in the frequency of periapical lesions.

CONCLUSIONS

Comparable rates of caries, periapical lesions and antemortem tooth loss in females and males indicate broad similarity in the diets of men and women. The greater levels of calculus and periodontal disease in males might point to some dietary differences, but could also be explained by non-dietary factors. Overall, the findings suggest that significant gender differences in diet, described in some contemporaneous textual sources, were not widely observed in Roman Britain.

The frequency and distribution of caries among the Iron Age population (about 2200 years BP) buried in the Mausoleum of Emperor Qinshihuang

OBJECTIVES

The purpose of this study was to assess the prevalence, distribution, and intensity of dental caries in the Iron Age population of northern China in order to increase knowledge about the type of food, dietary habit, and social stratification in this Iron Age people.

MATERIALS AND METHODS

The samples analyzed were dental remains of 1548 permanent teeth from 69 male individuals unearthed from the Qin archaeological site of Emperor Qinshihuang's Mausoleum in Lintong (northern China). The sex and the age-at-death of the samples were estimated.

RESULTS

Overall frequency of antemortem tooth loss in the samples was 0.8%. The proportion of individuals with at least one carious tooth was 65.2%, and the frequency of carious lesions was 9.4%, both showing a trend to rise as age increased. Data obtained on dental caries and antemortem tooth loss provided a corrected rate of 9.5% of teeth with caries. The most frequent carious lesions were occlusal lesions (2.6%), followed by interproximal (2.5%) and buccal/lingual lesions (1.0%). Tooth type analysis showed that molars had the highest percentage of caries (18.6%), followed by premolars (4.5%), canines (3.0%), and incisors (3.0%). The total SRCI was 1.6, increasing with age.

CONCLUSIONS

These findings indicate that dental caries may be related, at least in part, to the subsistence and diet of this Iron Age population.

The neolithic demographic transition and oral health: The Southeast Asian experience

The purpose of this article is to present new oral health data from Neolithic An Son, southern Vietnam, in the context of (1) a reassessment of published data on other Neolithic, Bronze, and Iron Age Southeast Asian dental series, and (2) predictions of the Neolithic Demographic Transition (NDT). To this end, frequencies for three oral conditions (caries, antemortem tooth loss, and alveolar lesions) were investigated for seven Southeast Asian adult dental series from Thailand and Vietnam with respect to time period, age-at-death and sex. A clear pattern of elevated rates for oral disease in the Neolithic followed by a marked improvement in oral health during the Bronze and Iron Ages was observed. Moreover, rates of caries and antemortem tooth loss for females were almost without exception higher than that for males in all samples. The consensus view among Southeast Asian bioarchaeologists that oral health did not decline with the adoption/intensification of agriculture in Southeast Asia, can no longer be supported. In light of evidence for (1) the low cariogenicity of rice; (2) the physiological predisposition of females (particularly when pregnant) to poorer oral health; and (3) health predictions of the NDT model with respect to elevated levels of fertility, the most plausible chief explanation for the observed patterns in oral health in Southeast Asia is increased levels of fertility during the Neolithic, followed by a decline in fertility during the subsequent Bronze and Iron Ages.

Dental caries prevalence as a product of agriculture and subsistence pattern at the Yean-ri site, South Korea

Yean-ri human skeletal remains from South Korea have been dated to the fourth to seventh century AD. They have morphological similarities to immigrants of the Yayoi period excavated in northern Kyushu and Yamaguchi prefecture in Japan. The overall dental caries prevalence was 8.1% in the Yean-ri skeletal remains, indicating a much lower prevalence than that of most Yayoi immigrant skeletal remains from Japan, although similar to that of the Kofun people (8.3%) in Japan. There was no significant difference in the dental caries prevalence between the males and females of the same age group, but there were differences in the prevalence by age. The late middle age and elderly males and females had significantly higher dental caries prevalence than the early middle age males and females, indicating increased prevalence with age. Root caries prevalence tended to increase in old age. The percentage of root caries increased, accounting for 80% of all caries in Yean-ri human skeletal remains. Agriculture is believed to have arisen approximately 3,000 years ago in Korea. Therefore, agriculture was practiced during this period, but since the Yean-ri tumuli are from coastal areas, their diet may have retained a significant marine component. Additionally, caries prevalence was not very high in Nukdo human remains (ca. 2100-2000 BC) in Korea. We speculate that they maintained subsistence activities suitable for their environment despite their knowledge of agriculture. This hypothesis is supported by differences in the caries prevalence between excavation sites of the Yayoi and Kofun periods in Japan.

Oral health and the postcontact adaptive transition: A contextual reconstruction of diet in Mórrope, Peru

This work explores the effects of European contact on Andean foodways in the Lambayeque Valley Complex, north coast Peru. We test the hypothesis that Spanish colonization negatively impacted indigenous diet. Diachronic relationships of oral health were examined from the dentitions of 203 late-pre-Hispanic and 175 colonial-period Mochica individuals from Mórrope, Lambayeque, to include observations of dental caries, antemortem tooth loss, alveolar inflammation, dental calculus, periodontitis, and dental wear. G-tests and odds ratio analyses across six age classes indicate a range of statistically significant postcontact increases in dental caries, antemortem tooth loss, and dental calculus prevalence. These findings are associated with ethnohistoric contexts that point to colonial-era economic reorganization which restricted access to multiple traditional food sources. We infer that oral health changes reflect creative Mochica cultural adjustments to dietary shortfalls through the consumption of a greater proportion of dietary carbohydrates. Simultaneously, independent skeletal indicators of biological stress suggest that these adjustments bore a cost in increased nutritional stress. Oral health appears to have been systematically worse among colonial women. We rule out an underlying biological cause (female fertility variation) and suggest that the establishment of European gender ideologies and divisions of labor possibly exposed colonial Mochica women to a more cariogenic diet. Overall, dietary change in Mórrope appears shaped by local responses to a convergence of colonial Spanish economic agendas, landscape transformation, and social changes during the postcontact transition in northern Peru. These findings also further the understandings of dietary and biocultural histories of the Western Hemisphere.

Oral health and frailty in the medieval English cemetery of St Mary Graces

The analysis of oral pathologies is routinely a part of bioarcheological and paleopathological investigations. Oral health, while certainly interesting by itself, is also potentially informative about general or systemic health. Numerous studies within modern populations have shown associations between oral pathologies and other diseases, such as cardiovascular disease, certain types of cancer, and pulmonary infections. This article addresses the question of how oral health was associated with general health in past populations by examining the relationship between two oral pathologies (periodontal disease and dental caries) and the risk of mortality in a cemetery sample from medieval England. The effects of periodontitis and dental caries on risk of death were assessed using a sample of 190 individuals from the St Mary Graces cemetery, London, dating to approximately AD 1350-1538. The results suggest that the oral pathologies are associated with elevated risks of mortality in the St Mary Graces cemetery such that individuals with periodontitis and dental caries were more likely to die than their peers without such pathologies. The results shown here suggest that these oral pathologies can be used as informative indicators of general health in past populations.

Change in diet and oral hygiene over an 8-week period: effects on oral health and oral biofilm

The aim of the study was to monitor changes in oral health and oral biofilm composition in vivo during an experiment simulating prehistoric lifestyle and diet and poor oral hygiene. Thirteen subjects lived for a period of 8 weeks under Neolithic conditions. The following clinical parameters were recorded before and after the project: gingival and plaque index (Löe and Silness, Acta Odontol Scand 21:533, 1963; Silness and Löe, Acta Odontol Scand 22:121-135, 1964), probing pocket depth, and bleeding upon probing. In addition, supragingival plaque samples were collected both before and after the project and were analysed quantitatively using multiplex fluorescence in situ hybridization and confocal laser scanning microscopy. The following plaque bacteria were evaluated: Streptococcus spp., Veillonella spp., Fusobacterium nucleatum, and Actinomyces naeslundii. The plaque index increased significantly from 1.12 up to 1.55 over the 8-week period (gingival index before, 0.46; after, 0.93; p < 0.05). A strong correlation of both indices was recorded before (r = 0.77) and after (r = 0.83) participation in the study. Each of the children in the study showed a progression of carious lesions and/or new areas of demineralisation. The probing pocket depth and bleeding upon probing were not affected. All subjects yielded an intra-individual shift in biofilm composition. The proportion of F. nucleatum decreased across all subjects. The proportion of Veillonella spp. increased among the children. Poor oral hygiene and change of diet lead to an increase in oral plaque and gingival inflammation. The inter-individual comparison indicated a shift in bacterial composition.

Relationship between root caries and alveolar bone loss in the first wet-rice agriculturalists of the Yayoi period in Japan

OBJECTIVE

The people of the Yayoi period (5th C b.c.-3rd C a.d.), who were the first wet-rice agriculturalists in ancient Japan, had carious lesions that were most frequently located on the root surfaces of their teeth. Root surface exposure is a prerequisite for this type of decay, and alveolar bone loss is the main cause of such exposure. Therefore, we identify the factors associated with root caries, and examine the relationship between root caries and alveolar bone loss in the people of the Yayoi period.

MATERIALS AND METHODS

This study was performed using 263 sets of ancient skeletal remains that are believed to be from the Yayoi period and that were excavated at 49 archaeological sites in western Japan. Using 5010 teeth found among the remains, we analysed the relationship between the prevalence of root caries and the cemento-enamel junction-alveolar crest (CEJ-AC) distance.

RESULTS

The prevalence of root caries and the mean number of teeth with root caries per person were significantly correlated with age, the presence of coronal caries and the mean CEJ-AC distance per person. We also found that as the mean CEJ-AC distance per tooth surface increased, the percentage of the root surface affected by caries increased. Moreover, after excluding the lingual (palatal) side, the mean CEJ-AC distance per surface was significantly greater for those tooth surfaces with root caries.

CONCLUSION

We present the first evidence that the occurrence of root caries correlated with the CEJ-AC distance in the Yayoi people of Japan.