Variability in dental caries prevalence between male and female foragers from the Late/Final Jomon period: Implications for dietary behavior and reproductive ecology

Assessing the existence of the male-female health-survival paradox in the past: Dental caries in medieval London

OBJECTIVES

This study seeks to identify signals of the male-female health-survival paradox in medieval London.

MATERIALS AND METHODS

This study uses skeletal data on age, sex, dental caries (n = 592) and antemortem tooth loss (n = 819) from adult individuals from medieval London cemeteries (c. 1200-1540 CE). The association between age and dental caries was assessed using binary logistic regression. The associations among age, time period (pre- vs. post-Black Death), oral biomarker (dental caries or antemortem tooth loss), and sex were tested using hierarchical log-linear analysis.

RESULTS

The analyses reveal significantly higher odds of dental caries with increasing adult ages, more older adults after the Black Death, different age distributions of dental caries between the sexes, and a greater decrease in the prevalence of dental caries for females after the Black Death. These results appear not to be an artifact of trends in AMTL. However, this study does not yield evidence suggesting that females experienced both a survival advantage and a decline in oral health at late adult ages after the Black Death relative to males.

CONCLUSIONS

These results do not provide evidence of the existence of a male-female health-survival paradox, but they do corroborate existing evidence of improvements in health in general in the aftermath of the Black Death. The decreased prevalence of dental caries after the Black Death may reflect dietary improvements or the effects of selective mortality during the epidemic.

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.

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.

Ecological and cultural shifts of hunter-gatherers of the Jomon period paralleled with environmental changes

OBJECTIVES

Holocene hunter-gatherers adapted to climatic and environmental changes over time. Carbon and nitrogen stable isotope analysis of human skeletal remains from the Inariyama shell mound of the Final Jomon period have revealed large dietary variations in the population. This study analyzed radiocarbon dates of these individuals to test temporal changes in diet and its relationship with tooth ablation.

MATERIALS AND METHODS

Twenty-nine human skeletal remains from Inariyama were included in this study. Extracted bone collagen samples were purified to graphite. Then, radiocarbon dating of these samples was performed using the accelerator mass spectrometer.

RESULTS

The radiocarbon ages of Inariyama ranged about, 3,230-2,140 cal BP and showed three peaks of occupation. In the early and late phases, terrestrial resource consumption and incisor extraction were observed, while marine resource consumption and canine extraction were observed in the middle phase.

DISCUSSION

These temporal changes of diet and tooth ablation types occurred in parallel with climatic cooling and environmental change and help reveal how Holocene hunter-gatherers adapted to the changing environments.

Diaphyseal cross-sectional geometry of the metatarsal bones in the Jomon population

OBJECTIVES

This study aimed to investigate differences in the diaphyseal cross-sectional geometry (CSG) of the metatarsal bones (MTs) between two populations with different habitual activities: the Jomon hunter-gatherers and modern Japanese people.

MATERIALS AND METHODS

We evaluated the first through fifth MTs of 117 skeleton samples: 59 (33 men and 26 women) were obtained from Late and Final Jomon period archeological sites and 58 (31 men and 27 women) were from modern Japanese people. CSG properties were calculated at the mid-shaft of the MTs and the relative values of the polar section modulus (Z_p ) of each second-to-fifth MTs to first MTs were calculated. These variables were compared according to population and sex.

RESULTS

Many of the CSG properties of MTs, except first MTs, were higher in the Jomon population than in the modern Japanese population for both sexes. Additionally, the relative values of the Z_p of the MTs were higher in Jomon men and women than in modern Japanese men and women. Moreover, the Jomon population had sex-based differences in the ratio of the shape of third MTs and fourth MTs and the relative MTs value. Jomon women had elliptical third MTs and fourth MTs, and the relative Z_p values of the third-to-fifth MTs to first MTs were higher in Jomon women than in Jomon men.

DISCUSSION

Our result suggests that the habitual activity of the Jomon population placed heavy loads on the forefoot. This finding possibly relates to mediolateral forefoot loading that appears to be related to traversing uneven terrain.

The characteristic mid-shaft cross-sectional shape of the ulna in Jomon hunter-gatherers

OBJECTIVES

The Jomon people were hunter-gatherers who inhabited the Japanese archipelago between 10,000 BC and 300 BC. Here, we focus on the mid-shaft cross-sectional shape of the ulna in the Jomon population and compare it with modern Japanese people.

MATERIALS AND METHODS

Jomon specimens, including 32 males and 22 females, were excavated from shell mound sites in the Pacific and Seto inland coastal area of Honshu island in the Japanese archipelago dated to the Late-to-Final Jomon phase (between 2,000 BC and 300 BC). Mid-shaft ulna cross-sectional shapes were compared with modern Japanese specimens (25 males, 21 females) using standard linear measurements and elliptic Fourier analysis (EFA). Differences from both sides of this element were compared using predicted handedness.

RESULTS

Linear measurements and EFA results show that ulna shape of both sexes within the Jomon population are relatively larger in the antero-posterior direction and have more developed posterior borders than modern Japanese males and females. No significant differences were observed between Jomon sexes based on the predicted dominant side, but differences were evident in the predicted nondominant side. At the same time, bilateral differences were recognized in Jomon females, because of a lower level of posterior border development in the predicted nondominant side compared to the dominant side.

DISCUSSION

Shape differences between Jomon people and modern Japanese can be explained by variation in the habitual loading of the ulna. Sexual dimorphism in ulna shape within the Jomon population suggests division of labor differences.

Ultrastructural and physico-chemical characterization of saliva during menstrual cycle in perspective of ovulation in human

Human saliva is a potential diagnostic fluid and any alteration in body might be reflected in saliva so that saliva is considered as "mirror of the body". Variations in salivary hormone level, ultra structure, pH, flow rate, buffering capacity and electrolytes level are found during menstrual cycle in regard to ovulation. Thirty healthy volunteers were used for the assessment of physico-chemical changes in saliva. Reproductive cycle was categorized as pre-ovulation phase (5 to 12 days), ovulation phase (13 or 14 days) and post-ovulation phase (15 to 25 days) according to salivary arborization test and hormonal analysis. Estradiol and luteinizing hormone was gradually increased and attained peak at the level of 2.28 ± 0.20 pg/mL and 1.35 ± 0.41 mIU/mL respectively during the ovulation phase. The electrolytes result clearly indicates that the influx of common electrolytes is important for crystallization and help to induce clear ferning pattern in ovulation phase. Sodium (Na) and chloride (Cl) were found to be high during ovulation phase only. Average salivary pH was 7.5, 7.1, and 7.3 during ovulation, pre- and post-ovulation phases respectively. Buffering capacity of saliva was normal during pre- and post- ovulation phases. In contrast, in ovulation phase the buffer capacity was slightly higher. At the first time, the scanning electron microscopy (SEM) studies revealed the ultra structure difference of saliva during menstrual cycle. During ovulation phase a compact network-shaped mesh was appeared; such structure was not appeared in pre- and post ovulation phases. Additionally, we observed the saliva is arrayed as a fine mosaic-like structure during ovulation. Based on physico-chemical properties and hormonal levels may lead to develop a detection kit/sensor for detecting the ovulation phase in human.

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.

Carbon isotope ratios of human tooth enamel record the evidence of terrestrial resource consumption during the Jomon period, Japan

OBJECTIVE

Archaeological remains strongly suggest that the Holocene Japanese hunter-gatherers, the Jomon people, utilized terrestrial plants as their primary food source. However, carbon and nitrogen isotope analysis of bone collagen indicates that they primarily exploited marine resources. We hypothesize that this inconsistency stems from the route of protein synthesis and the different proportions of protein-derived carbon in tooth enamel versus bone collagen. Carbon isotope ratios from bone collagen reflect that of dietary protein and may provide a biased signal of diet, whereas isotope ratios from tooth enamel reflect the integrated diet from all macronutrients (carbohydrates, lipids, and proteins).

METHODS

In order to evaluate the differences in inferred diet between the archaeological evidence and bone collagen isotope data, this study investigated carbon isotopes in Jomon tooth enamel from four coastal sites of the Middle to Late-Final Jomon period (5,000-2,300 years BP).

RESULTS

Carbon isotope ratios of human teeth are as depleted as coeval terrestrial mammals, suggesting that C₃ plants and terrestrial mammals were major dietary resources for the Jomon people. Dietary dependence on marine resources calculated from enamel was significantly lower than that calculated from bone collagen. The discrepancy in isotopic ratios between enamel and collagen and the nitrogen isotope ratio in collagen shows a negative correlation on individual and population levels, suggesting diets with variable proportions of terrestrial and marine resources.

CONCLUSION

This study highlights the usefulness of coupling tooth enamel and bone collagen in carbon isotopic studies to reconstruct prehistoric human diet. Am J Phys Anthropol 158:300-311, 2015. © 2015 Wiley Periodicals, Inc.

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 impact of gender on caries prevalence and risk assessment

Dental caries remains a common disease worldwide. There is evidence indicating that many caries risk factors provide a gender bias, placing women at a higher caries risk. Generally, dental caries disproportionally affects the poor and racial or ethnic minorities worldwide, with women suffering more from the disease. Differences in access to care as reflected by untreated caries rates also reflect gender disparities. There is a lack of evidence in regard to gender differences and dental caries. Therefore, there is an urgent need to develop the evidence necessary to meet the oral health needs of both women and men worldwide.