Nutritional supplementation and the development of linear enamel hypoplasias in children from Tezonteopan, Mexico

Nutritional supplementation, tooth crown size, and trait expression in individuals from Tezonteopan, Mexico

Understanding how epigenetic factors impact dental phenotypes can help refine the use of teeth for elucidating biological relationships among human populations. We explored relationships among crown size, principal cusp spacing, and accessory cusp expression in maxillary dental casts of nutritionally supplemented (n = 34) and non-supplemented (n = 39) individuals from Tezonteopan, Mexico. We hypothesized that the non-supplemented group would exhibit smaller molar crowns and reduced intercusp spacing. Since intercusp spacing is thought to be more sensitive to epigenetic influences than crown size, we predicted that the supplemented and non-supplemented groups would differ more in the former than the latter. Previous work suggests that molar accessory cusp expression may be elevated under conditions of stress. We therefore expected evidence of greater Carabelli and Cusp 5 trait expression in the non-supplemented group. We further hypothesized that anterior teeth would be affected by nutritional stress during development, with the non-supplemented group having smaller anterior tooth crowns and therefore limited space to form the tuberculum dentale. Finally, we tested whether the presence of molar accessory traits followed predictions of the Patterning Cascade Model of tooth morphogenesis in the entire sample. Our results supported the expectation that cusp spacing would differ more than molar crown size between the two groups. Carabelli trait showed little evidence of frequency differences between groups, but some evidence of greater trait scores in the non-supplemented group. The non-supplemented group also showed evidence of greater Cusp 5 frequency and expression. In the central incisors and canines, there was strong evidence for smaller crown sizes and reduced tuberculum dentale frequency in the non-supplemented group. With both groups pooled together, there was strong evidence of closer mesiodistal distances among principal cusps in molars with accessory cusps, a finding that is consistent with the PCM. Overall, our findings suggest that nutritional stress may affect accessory cusp expression.

Food insecurity and the dental team: a pilot study to explore opinions

PURPOSE

In total, 17% of UK households with children experience food insecurity, with evidence to suggest a direct correlation with the prevalence of oral disease. This study explores current perceptions of the dental team, when recognising and supporting families who may experience food insecurity.

MATERIALS AND METHODS

An online, anonymous cross-sectional survey was designed and sent to members of the British Society of Paediatric Dentistry (BSPD) in June 2023, examining confidence and understanding surrounding food insecurity and dental health. Quantitative data is presented descriptively and qualitative data using a thematic analysis.

RESULTS

The response rate was 9.6% (n = 76). A significant number recognise the link between poor oral health and food insecurity, 80.3% (n = 61). Although practitioners are confident in oral health counselling, 80.3% (n = 61) a smaller proportion are not as confident when approaching food insecurity 32.9% (n = 25). Dental team members recognise the need to improve identification of affected patients and that they have a professional duty to support. Intervention strategies, such as additional training to support team development and signposting of patients are indicated.

CONCLUSION

This study suggests that whilst dental professionals understand the link between food insecurity and oral health, and their responsibilities to those affected; they lack confidence in identifying such patients and providing support. Additional conversations and training are fundamental to better understand their role, which must reflect the needs of the population that they serve.

Association between Short Stature at Grade 1 and Permanent Teeth Caries at Grade 6 in Elementary School Children in Japan: A Population-Based Cohort Study

Short stature in children is a marker of low nutritional status and has been suggested to be associated with dental caries. However, longitudinal studies on this topic are scarce. Data from a longitudinal study of elementary school children in Adachi City, Tokyo, Japan, were analyzed. In 2015, caregivers of children at grade 1 answered questionnaires, and information on dental caries and height measured at school health checkups was merged and followed to grade 6 (N = 3576; follow up rate = 83.3%). The association between short stature at grade 1 (-2.01 standard deviation (SD)--3.00 SD, or <-3.00 SD in height-for-age according to the World Health Organization criteria) and the number of decayed, missing, or filled permanent teeth (DMFT) at grade 6 was examined using multivariable Poisson regression with robust standard error. After adjusting for confounders, children with a short stature at grade 1 had a higher DMFT number at grade 6: the mean ratios (95% confidence interval) were 1.17 (0.89-1.54) and 2.18 (1.03-4.64) for children with a height-for-age -2.01 SD--3.00 SD, and those with a height-for-age < -3.00, respectively. Short stature at grade 1 could be a marker of future dental caries in the permanent teeth at grade 6.

Gestational Serum Retinol Deficiency Is Associated with Enamel Hypoplasia

Enamel hypoplasia (EH) is a prevalent developmental defect of teeth that can result from various insults, including prenatal nutrient deficiencies. This study aimed to evaluate the association between prenatal serum retinol deficiency and EH in the deciduous teeth of offspring at 2-y of age. A cohort of 1,450 pregnant women was enrolled, and their prenatal nutritional status was assessed between 12 and 14 wk of gestation. Maternal serum retinol, serum 25-hydroxyvitamin D (25OHD), hemoglobin, body mass index, and birth outcomes, infant feeding practices, family socioeconomic status, and demographic information were recorded. Oral health examinations were conducted for the children semiannually, and EH was diagnosed using the Modified DDE index on all the surfaces of erupted teeth. A modified Poisson regression analysis was used to assess the cumulative risk of EH over a period of 2-y. A total of 920 (63.4%) mother-child pairs completed the study, and the cumulative EH prevalence among offspring after 2-y of follow-up was 16.5% (N = 152; 87/1,114 children in the first year and 132/920 in the second year, with 20/920 having EH only in the first year). After adjusting for potential confounders, maternal serum retinol deficiency significantly increased the risk of deciduous EH (risk ratio [RR], 2.0; 95% confidence interval [CI], 1.1-3.7). In addition, deficient serum 25OHD (RR, 6.5; 95% CI, 4.0-10.7), caesarean delivery (RR, 1.6; 95% CI, 1.0-2.4), Muslim (RR, 2.9; 95% CI, 2.0-4.1) and Christian (RR, 2.4; 95% CI, 1.6-3.5) versus Hindu religions, and very preterm birth (RR, 1.7; 95% CI, 1.1-2.9) increased the risk of EH. Children presenting with EH had 2 or more teeth affected, and the maxillary incisors were the most frequently affected, followed by the first primary molars and canines. In conclusion, maternal serum retinol deficiency during the 12 to 14 wk of gestation may increase the risk of deciduous EH, besides the well-established 25OHD deficiency.

From early to late modern societies (late 16th - early 20th century): Shifts in dental health status in two populations from southeastern France

In France, bioarcheological research has long overlooked the early and late modern periods, which witnessed major transformations impacting population structure and leading to the dawn of modern industrialized societies. Two recently excavated large cemeteries in Provence present a unique opportunity to investigate on a large scale the impact on health and living conditions brought about by the Industrial Revolution and consequently track health status changes from the 16th to the early 20th century. The sample includes 642 individuals from the early modern cemetery of Saint-Jacques, La Ciotat (1581-1831) and the late modern cemetery of Les Crottes, Marseille (1784-1905). This study aims to document dental health markers and compare the results between both assemblages, considering ante-mortem tooth loss, wear, caries, abscesses, calculus, periodontitis and linear enamel hypoplasia. The available archaeological and historical sources for these recent periods provide a full documentation in which to interpret and discuss the biological analysis, thus enabling an inclusive bioarcheological approach. RESULTS: revealed similarities between both samples. Differences are more subtle than expected and are seen through the increase in carious lesions and in linear enamel hypoplasia. The former seem to indicate changes in diet with the introduction of new foodstuffs and manufacturing processes during the Industrial Revolution. The latter could reflect the increase in early childhood stress, perhaps due to new feeding practices around weaning and breastfeeding or a poorly diversified diet. Finally, the increasing number of stress events could suggest a noxious sanitary and infectious environment. During the 19th century, Marseille experienced strong demographic and urban growth, resulting in overcrowded areas where sanitation facilities were insufficient or absent. Moreover, the activity of this important trading seaport might have promoted the transmission and appearance of epidemic diseases despite scientific and medical advances, which would have a real impact only from the 20th century onwards.

Skeletal evidence of structural violence among undocumented migrants from Mexico and Central America

OBJECTIVES

We examine the prevalence and sociodemographic risk factors of skeletal indicators of stress in forensic samples of undocumented migrants from Mexico and Central America.

MATERIALS AND METHODS

Cranial and dental remains of 319 migrants recovered in the Arizona and Texas borderlands were assessed for porotic hyperostosis (PH), cribra orbitalia (CO), and linear enamel hypoplasias (LEH). Logistic regression models for each condition were estimated to test for associations with biological sex, age, recovery location, and whether individuals were identified. Additional models estimated for a subsample of identified migrants included region of origin, residential context, and community indigeneity.

RESULTS

The full sample shows moderate crude prevalence of CO (9.6%) and LEH (34.1%), and a high prevalence of PH (49.6%). Significantly higher odds of PH are associated with being male (2.16 times higher), unidentified (1.89 times higher), and recovered in Arizona (3.76 times higher). Among identified migrants, we fail to find associations significant at the p < 0.05 level between skeletal stress and all sociodemographic variables except age.

DISCUSSION

The factors associated with PH may be related to influences on decisions to migrate and diversity among migrant sending regions. The skeletal evidence for early life stress is generally consistent with common public health concerns among impoverished communities in the region. The lesions themselves are viewed as embodied risk of physiological disturbance when resource access is structured by higher-level social, economic, and political forces. Forensic anthropologists would benefit from increased sensitivity to embodied structural violence among the vulnerable individuals and communities they serve.

An integrative approach to studying plasticity in growth disruption and outcomes: A bioarchaeological case study of Napoleonic soldiers

OBJECTIVES

The aim of this study was to investigate how much variation in adult stature and body mass can be explained by growth disruption among soldiers who served in Napoleon's Grand Army during the Russian Campaign of 1812.

METHODS

Linear enamel hypoplasia (LEH) were recorded as representations of early life growth disruption, while the impact on future growth was assessed using maximum femur length (n = 73) as a proxy for stature and maximum femoral head diameter (n = 25) as a proxy for body mass. LEH frequency, severity, age at first formation, and age at last formation served as explanatory variables in a multiple regression analysis to test the effect of these variables on maximum femur length and maximum femoral head diameter.

RESULTS

The multiple regression model produced statistically significant results for maximum femur length (F-statistic = 3.05, df = 5 and 67, P = .02), with some variation in stature (adjusted r² = 0.13) attributable to variation in growth disruption. The multiple regression model for maximum femoral head diameter was not statistically significant (F-statistic = 1.87, df = 5 and 19, P = .15).

CONCLUSIONS

We hypothesized stress events during early life growth and development would have significant, negative, and cumulative effects on growth outcomes in adulthood. The results did not support our hypothesis. Instead, some variables and interactions had negative effects on stature, whereas others had positive effects. This is likely due to catch-up growth, the relationship between acute and chronic stress and growth, resilience, and plasticity in human growth over the life course.

Insights on patterns of developmental disturbances from the analysis of linear enamel hypoplasia in a Neolithic sample from Liguria (northwestern Italy)

OBJECTIVE

To assess developmental disturbances through the analysis of linear enamel hypoplasia (LEH) frequency and to infer environmental stress and life history within Neolithic communities from Liguria (Italy).

MATERIALS

43 unworn/minimally worn permanent anterior teeth of 13 individuals recovered from nearby caves and dated to c. 4800-4400 cal. BCE.

METHODS

LEH defects were identified with high-resolution macrophotos of dental replicas, age at LEH was calculated via perikymata counts. LEH defects matched between two or more teeth were considered as systemic disturbances. LEH frequency by age classes was analyzed via GLZ and Friedman ANOVA.

RESULTS

Number of matched defects per individual range between 2-12. The mean LEH per individual was highest in the 2.5-2.99 age category, with a significant increase relative to earlier growth stages, followed by a decline.

CONCLUSION

LEH may reflect life-history in the local ecology of Neolithic Liguria, where several individuals with osteoarticular tuberculosis have been recorded. Disease burden may have triggered developmental disturbances around the time of weaning. Age at first defect was negatively correlated with age at death and positively with the total number of defects, suggesting that early stress may have affected survivorship.

SIGNIFICANCE

The study contributes to the reconstruction of ecological pressures among Neolithic people of Liguria, and informs on environmental challenges during the Neolithic adaptive expansion.

LIMITATIONS

The visual examination of macrophotos is prone to observer error; mid-crown tends to display more visible LEH due to tooth architecture.

SUGGESTIONS FOR FURTHER RESEARCH

Apply different quantitative methods to examine severity and duration of disturbances.

Valkyries: Was gender equality high in the Scandinavian periphery since Viking times? Evidence from enamel hypoplasia and height ratios

Scandinavian countries currently have very high values of female autonomy. Was this already the case in Viking Times? In this study, we trace the roots of gender equality in the Scandinavian periphery over the past two millennia. We evaluate and recommend a new measure of early gender equality: relative enamel hypoplasia values of males and females. This new indicator allows us to trace relative health and nutritional equality, using archaeological evidence. We find that Scandinavian women in the rural periphery already had relatively good health and nutritional values during the Viking era and the medieval period thereafter. The corresponding value is 0.8 equality advantage for Scandinavian women, whereas in the rest of Europe most values fall in a band around 1.2 ratio units. This suggests that the currently high gender equality had a precedence during the Middle Ages.

Malnutrition-related early childhood exposures and enamel defects in the permanent dentition: A longitudinal study from the Bolivian Amazon

OBJECTIVES

We investigated the relationship between early childhood malnutrition-related measures and subsequent enamel defects in the permanent dentition.

MATERIALS AND METHODS

This cohort study included 349 Amerindian adolescents (10-17 years, 52% male) from the Bolivian Amazon. Exposures included: stunted growth (height-for-age z-scores), underweight (weight-for-age z-scores), anemia (hemoglobin), acute inflammation (C-reactive protein) and parasitic infection (hookworm). We measured the occurrence (no/yes) and extent (<1/3, 1/3-2/3, >2/3) of enamel defects. We estimated associations between childhood exposures and enamel defect measures using log-binomial and multinomial logistic regression.

RESULTS

The prevalence of an enamel defect characterized by an orange peel texture on a large central depression on the labial surface of the central maxillary incisors was 92.3%. During childhood (1-4 years), participants had a high prevalence of stunted growth (75.2%), anemia (56.9%), acute inflammation (39.1%), and hookworm infection (49.6%). We observed associations between childhood height-for-age (OR = 0.65; P = 0.028 for >2/3 extent vs. no EH) and gastrointestinal hookworm infection (OR = 3.43; P = 0.035 for >2/3 extent vs. no defects or <1/3 extent) with enamel defects.

DISCUSSION

The study describes a possibly novel form of enamel hypoplasia and provides evidence for associations of malnutrition-related measures in early childhood, including stunted growth and parasitic helminth infection, with the observed enamel defects.

Stressing out in medieval Denmark: An investigation of dental enamel defects and age at death in two medieval Danish cemeteries

The influence of early life stress on later life experiences has become a major focus of research in medicine and more recently in bioarchaeology. Dental enamel, which preserves a record of childhood stress events, represents an important resource for this investigation when paired with the information from adult skeletal remains, such as age at death. The purpose of this research was to use a life history approach to the exploration of sex differences in the relationship between childhood stress and adult longevity by examining accentuated striae of Retzius (AS). A medieval Danish sample (n=70) drawn from the rural cemetery of Sejet and the urban cemetery of Ole Wormsgade was considered for AS and age at death. The results suggest sex differences in survivorship, with more stress being associated with reduced survivorship in males and increased survivorship in females. A consideration of AS formation time also suggests a difference in the impact of developmental timing between males and females. These results are interpreted in terms of differential frailty and selective mortality, drawing in both biomedical and cultural perspectives.

Regional differences in health, diet and weaning patterns amongst the first Neolithic farmers of central Europe

Across much of central Europe, the Linearbandkeramik (LBK) represents the first Neolithic communities. Arising in Transdanubia around 5500 cal. BC the LBK spread west to the Rhine within two to three hundred years, carrying elements of a mixed agricultural economy and a relatively homogeneous material culture. Colonisation of new regions during this progress would have required economic adaptations to varied ecological conditions within the landscape. This paper investigates whether such adaptation at a local scale affected health patterns and altered the dietary habits of populations that otherwise shared a common cultural and biological origin. Analysis of non-specific stress (linear enamel hypoplasia, porotic hyperostosis, cribra orbitalia) within five LBK populations from across central Europe in conjunction with published carbon and nitrogen stable isotope data from each site revealed a high prevalence of porotic hyperostosis and cribra orbitalia in western populations that was associated with a lower animal protein intake. Hypoplastic enamel was more frequently observed in eastern populations however, and may reflect geographic differences in childhood morbidity and mortality as a result of variation in social practices relating to weaning. Local socio-economic adaptations within the LBK were therefore an important factor in the exposure of populations to non-specific stress.

Oral health in prehistoric San Pedro de Atacama oases, Northern Chile

After almost 2000 years of local development, including limited trading with neighboring ethnic groups, the societies that occupied the oases of San Pedro de Atacama, Northern Chile, became part of the trade web of the Tiwanaku empire, between 500 and 1000 CE. Archaeological evidence tends to support the idea that the period under the influence of the altiplano (high plane) empire was very affluent. Here we investigate the possibility that this affluence had a positive impact on the health status of the Atacameneans, using the oral health as an indirect indicator of quality of life. Dental decay, dental abscess, dental wear, linear enamel hypoplasia, periodontal disease and dental calculus were analyzed on 371 skeletons from 12 sites from San Pedro de Atacama oases. We believe that if, indeed, there were better biological conditions during the altiplano influence, this could have been caused by the access to a more diversified food intake promoted by the intensification of the trading network established by Tiwanaku in the central-south Andes, of which San Pedro de Atacama became an important node.

Skeletal manifestations of stress in child victims of the Great Irish Famine (1845-1852): prevalence of enamel hypoplasia, Harris lines, and growth retardation

The Great Irish Famine of 1845-1852 is among the worst food crises in human history. While numerous aspects of this period have been studied by generations of scholars, relatively little attention has so far been given to the physiological impact it is likely to have had on the people who suffered and succumbed to it. This study examines the prevalence of enamel hypoplasia, Harris lines, and growth retardation in the nonadult proportion of a skeletal population comprising victims of the Famine who died in the workhouse in the city of Kilkenny between 1847 and 1851. The frequency of enamel hypoplasia in these children does not appear to have increased as a consequence of famine, although this fact is likely to be a reflection of the osteological paradox. Harris lines and growth retardation; however, were very prevalent, and the manifestation and age-specific distribution of these may be indicators of the Famine experience. While there was no clear correlation in the occurrence of the assessed markers, the presence of cribra orbitalia displayed a significant relationship to enamel hypoplasia in 1- to 5-year-old children. While starvation, metabolic disorders and infectious diseases are likely to have greatly contributed to the manifestation of the markers, the psychosocial stress relating to institutionalization in the workhouse should not be underestimated as a substantial causative factor for skeletal stress in this population.

Early childhood caries and its relationship with perinatal, socioeconomic and nutritional risks: a cross-sectional study

Background

Socioeconomic, perinatal and other life cycle events can be important determinants of the health status of the individual and populations. This study aimed to assess the prevalence of early childhood caries (ECC), perinatal factors (gestational age, teenage pregnancy and birth weight), family income and nutritional risk in children.

Methods

A cross-sectional study in which 320 children were examined according to the criteria established by the World Health Organization. A previously validated questionnaire was used to obtain information from parents and guardians about family income, gestational age and birth weight. To check the nutritional risk, we used the criteria provided by the CDC (Center for Disease Control). For Statistics, Pearson’s, chi-square and the multivariate Poisson analyses were used to determine the association among variables.

Results

Approximately 20% of children had ECC, and the Poisson multivariate analyses indicated that family income (p = 0.009), birth weight (p < 0.001) and infant obesity (p < 0.001) were related to the increase of ECC, and gestational age was not significantly associated with ECC (p = 0.149). Pregnancy in adolescence was not included in the regression analyses model because it was not statistically significant in the chi-square test (p > 0.05).

Conclusion

The prevalence of ECC was related to low family income, premature birth and infant obesity.

A comparative study of stress episode prevalence and duration among Jomon period foragers from Hokkaido

This study reconstructs linear enamel hypoplasia (LEH) prevalence and stress episode duration among Jomon period foragers from Hokkaido, Japan (HKJ). Results are compared to Jomon period samples from coastal Honshu, Japan (HSJ) and Tigara Inupiat from Point Hope, Alaska (PHT) to provide a more comprehensive perspective on the manifestation of stress among circum-Pacific foragers. LEH were identified macro- and microscopically by enamel surface depressions and increased perikymata spacing within defects. Individuals with more than one anterior tooth affected by LEH were labeled as LEH positive. Stress episode durations were estimated by counting the number of perikymata within the occlusal wall of each LEH and multiplying that number by constants reflecting modal periodicities for modern human teeth. LEH prevalence and stress episode duration did not differ significantly between the two Jomon samples. Significantly greater frequencies of LEH were found in HKJ as compared to PHT foragers. However, HKJ foragers had significantly shorter stress episode durations as compared to PHT. This suggests that a greater proportion of HKJ individuals experienced stress episodes than did PHT individuals, but these stress events ended sooner. Similarity in stress experiences between the two Jomon samples and differences between the HKJ and PHT are found. These findings are important for two reasons. First, stress experiences of foraging populations differ markedly and cannot be generalized by subsistence strategy alone. Second, due to significant differences in episode duration, stress experiences cannot be understood using prevalence comparisons alone.

Linear enamel hypoplasia and growth in an Australian Aboriginal community: Not so small, but not so healthy either

BACKGROUND

While much is strongly suspected about synergisms linking courses of growth and development with nutrient intakes, immune function, disease exposures, and energy expenditures, debates remain regarding the probability of permanent impairments to growth and function under various circumstances.

AIM

This study tests a series of related hypotheses in an attempt to reconcile evidence of increasing physiological stress among Warlpiri and Pintubi infants and young children following settlement in the 1940s with their frequently rapid and undelayed longitudinal growth in stature during adolescence.

SUBJECTS AND METHODS

The study used archived cross-sectional and longitudinal records of stature, weight, and dental casts collected by the Dental School at the University of Adelaide beginning in 1951 at the then recently settled community of Yuendumu. Longitudinal modelling of height data and all statistical tests were accomplished using SYSTAT 10. Height, weight, and BMI (kg m-2) for age z-scores were calculated using NCHS reference data. Dental casts were scored for linear enamel hypoplasia (LEH) with each defect assigned to an enamel developmental unit. The extent of height catch-up was estimated using conditional height gain.

RESULTS

Cross-sectional analyses indicate significant associations between birth year and women's heights (n = 105, p = 0.02) or height for age z-scores (p = 0.003), but no similar associations among men. Final height for age z-score was significantly associated with sex (p < 0.0005), onset (p = 0.031), and an onset by number of enamel defects interaction (p = 0.033). Late adolescent height z-scores were only significantly negatively associated with increasing numbers of defects among individuals with enamel defects appearing prior to about 18 months of age (n = 60, p = 0.019). With longitudinally estimated age at peak height velocity (APHV) statistically controlled, peak height velocity (PHV) was similarly significantly positively associated with conditional height gain in males (n = 50, p = 0.01) and females (n = 31, p = 0.05). Exploratory analyses suggest that with timing and intensity of PHV controlled, childhood body mass was only significantly positively associated with catch-up in height among those who experienced defect onset relatively early (n = 80, p = 0.005).

CONCLUSION

Results help explain previously documented, and apparently contradictory, outcomes of settlement processes. Rapid and relatively undelayed late childhood and adolescent growth associated with catch-up in height occurred through a confluence of increasing early childhood systemic stress followed by increases in net energy consumption that probably increased as children aged.

Patterns in dental enamel hypoplasia by sex and age at death in two archaeological populations

AIMS

Levels of enamel hypoplasia in past populations are frequently used to study health. However, few studies have looked at patterning in the occurrence of different types of hypoplasia. In this pilot study, skeletal remains from an Iron Age tomb at Pella in Jordan were analysed for the presence of linear and pit enamel hypoplasia, to investigate enamel hypoplasia aetiology by comparison of the results obtained for adults and juveniles, and females and males.

METHODS AND RESULTS

The proportion of individuals with enamel hypoplasia was determined for males and females and for adults and juveniles using the F.D.I. Developmental Defects of Enamel (DDE) Index. Although males and females had a similar percentage of individuals affected, females had a higher prevalence of enamel hypoplasia per tooth than males. Adults had a higher prevalence of enamel hypoplasia than juveniles. In particular, adults had a higher prevalence of linear enamel hypoplasias and pit enamel hypoplasia arrays, but a similar prevalence of single pit enamel hypoplasia when both the permanent and deciduous dentitions were considered. These differences were largely due to different patterns and frequencies of enamel hypoplasia in deciduous teeth compared to permanent teeth.

CONCLUSIONS

The different patterns of occurrence of the various forms of hypoplasia observed in this study imply that single pits may have a different aetiology to linear enamel hypoplasias and pit arrays. By investigating similar patterns in other archaeological populations, we may develop a better understanding of the specific causes of particular types of enamel hypoplasia, and may be able to more meaningfully interpret enamel hypoplasia data from past populations.

[Socioeconomic factors, nutritional risk, and enamel defects in children from João Pessoa, Paraíba State, Brazil]

This study focused on factors related to nutritional risk in children over one year of age from low-income families in João Pessoa, Paraíba State, Northeast Brazil, and the frequency of related enamel defects. The study included 117 children, 56 at nutritional risk and 61 with normal growth. Nutritional evaluation, clinical dental examination, and interviews with mothers were conducted at the homes. Gestational and birth records were examined in the maternity hospital. Data were analyzed using the chi-square, Fisher's exact tests, and logistic regression. Enamel defects were associated with nutritional risk after the first year of life. Nutritional risk was associated with per capita family income, birth weight, and intrauterine growth index. These are relevant factors for individual nutritional planning and formation of dental enamel.

Dietary variation and stress among prehistoric Jomon foragers from Japan

Current archaeological evidence indicates that greater dietary reliance on marine resources is recorded among the eastern Jomon, while plant dependence prevailed in western/inland Japan. The hypothesis that the dietary choices of the western/inland Jomon will be associated with greater systemic stress is tested by comparing carious tooth and enamel hypoplasia frequencies between the eastern and western/inland Jomon. Demographic collapse coincides with climate change during the Middle to Late Jomon period, suggesting dwindling resource availability. It is hypothesized that this change was associated with greater systemic stress and/or dietary change among the Middle to Late Jomon. This hypothesis is tested by comparing enamel hypoplasia and carious tooth frequencies between Middle to Late and Late to Final Jomon foragers. Enamel hypoplasia was significantly more prevalent among the western/inland Jomon. Such findings are consistent with archaeological studies that argue for greater plant consumption and stresses associated with seasonal resource depletion among the western/inland Jomon. Approximately equivalent enamel hypoplasia frequencies between Middle to Late and Late to Final Jomon foragers argues against a demographic collapse in association with diminished nutritional returns. Significant differences in carious tooth frequencies are, however, observed between Middle to Late and Late to Final Jomon foragers. These results suggest a subsistence shift during the Middle to Late Jomon period, perhaps in response to a changed climate. The overall patterns of stress documented by this study indicate wide-spread environmentally directed biological variation among the prehistoric Jomon.

Dental enamel hypoplasias and health changes in the Middle Bronze Age – Early Iron Age transition at Pella in Jordan

Dental enamel hypoplasias are increasingly being used in epidemiological studies as indicators of health within both modern and prehistoric populations. This symptom of growth disruption is used here to examine possible changes in health occurring at the transition between the Bronze Age and Iron Age in Jordan, through examination of enamel hypoplasias in skeletal remains from two tombs at the archaeological site of Pella. A small but not statistically significant difference in the prevalence and frequency of hypoplastic defects was found between the two time periods. These results suggest that the political and economic changes occurring at this time were not sufficiently stressful to cause a dramatic deterioration in health at the onset of the Early Iron Age.

Focused life history data and linear enamel hypoplasia to help explain intergenerational variation in relative leg length within Taiwanese families

This study first examines the hypothesis that significant intergeneration increases in stature within 85 Taiwanese families in two study locations were primarily the result of increases in subischial leg length. It then evaluates a second hypothesis that independent assessments of the extent of intergenerational change in childhood environments within these families helped account for parent-offspring differences in relative leg length. Childhood environments were assessed using two criteria: developmental environment scores derived from life history data and evidence of linear enamel hypoplasia (LEH). Relative leg length was represented in two ways, as either the difference between internally estimated sex-specific z-scores of sitting height and subischial leg length (z(D) = z(SH) - z(LL)) or as relative sitting height (RSH; sitting height/height x 100). Paired Student t tests indicated intergenerational increases in relative leg length were significantly greater than zero in both study locations (P < or = 0.012). The second hypothesis, tested using a hierarchical model with maximum likelihood estimation that allowed for nesting of more than one offspring per family, received support as midparent-offspring differences in composite scores were significantly positively associated with midparent-offspring differences in relative leg length. This was true alone (P = 0.018), and when significant associations with LEH prevalence among mothers and offspring were statistically controlled for (P = 0.010). Evidence also indicated that while the large majority of offspring were taller than their midparental average height (84.3%; 91/108), offspring who were taller were also more likely to have relatively longer legs than by chance alone (Fishers exact, P = 0.027).

Alimentação, estado nutricional e condição bucal da criança

A relação entre alimentação, estado nutricional e a condição bucal ainda não está bem esclarecida, apresentando, muitas vezes, versões controversas e conhecimento limitado. Existe certa concordância de que a alimentação e, conseqüentemente, o estado nutricional, possam exercer certa influência sobre a condição bucal imediata e futura da criança. O objetivo desta comunicação é apresentar possíveis relações entre alimentação, estado nutricional e a condição bucal da criança. O estado nutricional pode afetar os dentes durante o seu período de formação e após a erupção na cavidade bucal. Os efeitos sistêmicos provenientes da nutrição podem alterar o desenvolvimento dos dentes, a quantidade e a qualidade da saliva, assim como os efeitos externos também podem determinar uma maior prevalência de cárie dentária, uma vez que tanto a quantidade de sacarose ingerida, quanto a freqüência de ingestão são importantes fatores envolvidos em sua etiologia. As reflexões deste trabalho sugerem a necessidade de ações interdisciplinares para obtenção de resultados na prevenção e no tratamento das doenças bucais.

Brief Communication: Linear enamel hypoplasia and the shift from irregular to regular provisioning in Cayo Santiago rhesus monkeys (Macaca mulatta)

This study investigates changes in the prevalence of linear enamel hypoplasia (LEH) before and after the shift from irregular to regular provisioning in the Cayo Santiago rhesus monkey population. Prior to 1956, monkeys on this island colony did not receive consistent provisions, and were reported to be in poor health (Rawlins and Kessler [1986] The Cayo Santiago Macaques; Albany: State University of New York Press). A regular provisioning program, instituted in August 1956, resulted in the improved health of individuals and the growth of the population (Rawlins and Kessler [1986] The Cayo Santiago Macaques; Albany: State University of New York Press). LEH, a developmental defect of enamel, is a sensitive indicator of systemic physiological stress (Goodman and Rose [1990] Yrbk. Phys. Anthropol. 33:59-110). It was therefore hypothesized that the prevalence of LEH would be higher in monkeys who were irregularly provisioned than in monkeys who experienced regular provisioning. To test this hypothesis, teeth were examined for LEH in a sample of 181 female rhesus monkeys. The results support the hypothesis: the mean number of defects was statistically significantly higher in the preprovisioned group than it was in the postprovisioned one. When LEH prevalence was assessed using only defects occurring on antimeric pairs, the preprovisioned group again had a higher prevalence than the postprovisioned one, although the difference was not statistically significant, most likely because of the reduced sample size. The results of this study indicate that changes in LEH prevalence, at least in this population of rhesus monkeys, are associated with changes in nutritional status.

Linear enamel hypoplasias as indicators of systemic physiological stress: evidence from two known age-at-death and sex populations from postmedieval London

Enamel hypoplasias are useful indicators of systemic growth disturbances during childhood, and are routinely used to investigate patterns of morbidity and mortality in past populations. This study examined the pattern of linear enamel hypoplasias in two different burial populations from 18th and 19th Century church crypts in London. Linear enamel hypoplasias on the permanent dentitions of individuals from the crypt of Christ Church, Spitalfields, were compared to enamel defects on the teeth of individuals from St. Bride's. The method used involves the identification of enamel defects at a microscopic level, and systemic perturbations are detected by matching hypoplasias among different tooth classes within each individual. The pattern of linear enamel hypoplasias was contrasted between individuals from the burial sites of Spitalfields and St. Bride's, between males and females, and between those aged less than 20 years of age and those aged over 20 years at death. Six different parameters were examined: frequency of linear enamel hypoplasias, interval between defects, duration of hypoplasias, age at first occurrence of hypoplasia, age at last occurrence of hypoplasia, and the percentage of enamel formation time taken up by growth disturbances. All individuals in the study displayed linear enamel hypoplasias, with up to 33% of total visible enamel formation time affected by growth disruptions. Multiple regression analysis indicated a number of significant differences in the pattern of enamel hypoplasias. Individuals from Spitalfields had shorter intervals between defects and greater percentages of enamel formation time affected by growth disturbances than did individuals from St. Bride's. Females had greater numbers of linear enamel hypoplasias, shorter intervals between defects, and greater percentages of enamel formation time affected by growth disturbances than males. There were also differences in the pattern of enamel hypoplasias and age at death in this study. Individuals who died younger in life had an earlier age at first occurrence of enamel hypoplasia than those who survived to an older age. The pattern of enamel hypoplasias detected in this study was influenced by tooth crown geometry and tooth wear such that most defects were found in the midcrown and cervical regions of the teeth, and greater numbers of defects were identified on the anterior teeth. Differences in sensitivity of the parameters used for the detection of enamel hypoplasias were found in this study. The percentage of visible enamel formation time affected by growth disturbances was the parameter that identified the greatest number of significant differences among the subgroups examined.

Malnutrition and dental caries: a review of the literature

Protein-energy malnutrition occurs when there are deficiencies in protein, energy foods or both, relative to a body's needs. This paper reviews the association of early childhood malnutrition with: (1) dental caries, (2) enamel hypoplasia, (3) salivary gland hypofunction, and (4) delayed eruption. Studies suggest that caries of the primary dentition is associated with early childhood malnutrition, though the effect on caries of the permanent dentition has essentially not been studied. Enamel hypoplasia, salivary glandular hypofunction and saliva compositional changes may be mechanisms through which malnutrition is associated with caries, while altered eruption timing may create a challenge in the analysis of age-specific caries rates.

Life stress on the Roman limes in continental Croatia

The purpose of the paper is to analyze and compare the demographic profiles and disease frequencies between a skeletal series from Zmajevac, a settlement on the Danubian limes, and a composite "non-limes" skeletal series consisting of human osteological remains from three large urban settlements to the west of the limes; roman Mursa (modern Osijek), Cibalae (Vinkovci) and Certissia (Strbinci). To determine if life stresses were different in settlements on the limes the age and sex distribution in Zmajevac was compared to the composite "non-limes" series. All skeletons were also analyzed for the presence of dental pathology, dental enamel hypoplasia, cribra orbitalia, trauma, and physical stress. Data collected from the skeletal series show that, with the exception of some indicators of physical stress, no significant differences in quality of life is evident. Both series are characterized by an under-representation of subadults from the youngest age category and by similar average adult male and female ages at death. In Zmajevac the average ages at death for adult males and females were 40.0 and 39.0 years respectively, in the composite "non-limes" series 37.4 years for both males and females. The frequencies of dental disease, subadult stress indicators, and trauma are similar in both series. The only consistent difference between the two series is noted in the frequencies of skeletal markers of physical stress, in particular the frequencies of vertebral osteoarthritis and Schmorl's defects. Total male and total female vertebral osteoarthritis frequencies in the two series are significantly different, as is the difference in total male frequencies of Schmorl's defects. Young adult males in the Zmajevac series seem to have been experiencing particularly heavy physical strain on the vertebral column. They exhibit significantly higher frequencies of both vertebral osteoarthritis and Schmorl's defects than young adult males from the composite non-limes series.

Rapid morphological change in living humans: implications for modern human origins

Human body size and body proportions are interpreted as markers of ethnicity, 'race,' adaptation to temperature, nutritional history and socioeconomic status. Some studies emphasize only one of these indicators and other studies consider combinations of indicators. To better understand the biocultural nature of human size and proportions a new study of the growth of Maya-American youngsters was undertaken in 1999 and 2000. One purpose of this research is to assess changes in body proportion between Maya growing up in the US and Maya growing up in Guatemala. Height and sitting height of 6-12-year-old boys and girls (n=360) were measured and the sitting height ratio [sitting height/height]x100, a measure of proportion, was calculated. These data are compared with a sample of Maya of the same ages living in Guatemala and measured in 1998 (n=1297). Maya-American children are currently 10.24 cm taller, on average, and have a significantly lower sitting height ratio, (i.e. relatively longer legs, averaging 7.02 cm longer) than the Guatemala Maya. Maya-American children have body proportions more like those of white children in the US than like Maya children in Guatemala. Improvements in the environment for growth, in terms of nutrition and health, seem to explain both the trends in greater stature and relatively longer legs for the Maya-Americans. These findings are applied to the problem of modern human origins as assessed from fossil skeletons. It has been proposed that heat adapted, relatively long-legged Homo sapiens from Africa replaced the cold adapted, relatively short-legged Homo neandertalensis of the Levant and Europe [J Hum Evol 32 (1997a) 423]. Skeletal samples of Maya adults from rural Guatemala have body proportions similar to adult Neandertals and to skeletal samples from Europe with evidence of nutritional and disease stress. Just as nutrition and health status explains the differences in the body proportions of living Maya children, these factors, along with adaptation to climate, may also explain much of the differences between the Neandertal and African hominid samples.

Caries and micronutrient intake among urban South African children: a cohort study

OBJECTIVE

To report on associations between caries and micronutrient intake among a 'true cohort' group of 5-year-old urban black South African children.

METHODS

The study sample was a true cohort that had nutrition as well as dental information for 1991 and 1995 (n = 259). Micronutrient intake and dental caries associations were examined with SAS using the linear logistic analysis and a critical level of statistical significance of P < 0.05.

RESULTS

Of the 21 micronutrients investigated, vitamin B12, riboflavin, magnesium and biotin were individually significantly associated with caries incidence, but taken together only magnesium was significant.

CONCLUSIONS

The association of micronutrient intake with caries was weak, isolated and not clinically relevant. Micronutrient intake was not an indicator of the presence or absence of caries among the children studied.

Diet and health changes at the end of the Chinese neolithic: the Yangshao/Longshan transition in Shaanxi province

In this paper we discuss diet and health changes of millet agriculturists in Northern China, Shaanxi province, during the period 7,000-4,000 BP. An episode of intensive climatic oscillations that preceded the onset of colder climate circa the fifth millennium BP divides the period (Shi et al. [1993] Global Planet. Change 7:219-233). The onset of the cooler climate marks the decline of the egalitarian society of Yangshao and the rise of the chiefdom-like society of Longshan. Skeletal materials from the two sites of Beiliu and Jiangzhai are from the earlier phases of Yangshao culture (7,000-6,000 BP), while remains from the Shijia site were excavated from the terminal phase of Yangshao culture (6,000-5,000 BP), a phase that would be expected to show adjustments to strong climatic fluctuations. Human remains from the Longshan culture (5,000-4,000, BP) were found at the Kangjia site. In order to investigate whether the trajectory of diet and health changes persisted beyond the Longshan, a skeletal sample from the Xicun site of the Western Zhao Dynastic period (3,800-2,200 BP) is included in our analyses. All Yangshao sites in our study are characterized by low frequencies of anemia and carious lesions. Some subsistence changes probably occurred during the later phase of Yangshao culture that resulted in elevated masticatory stress and occlusal macrowear among the Shijia people. However, deterioration of community health did not begin until the Longshan, when increased occurrence of porotic hyperostosis and caries is accompanied by decreased adult stature. The transition to softer, more extensively processed food during Longshan is evident in decreased rates of occlusal wear. Increased population density and diminished food values were most likely responsible for these changes. Poor health persisted into the subsequent Dynastic period of Western Zhao.

A detailed study of enamel hypoplasia in a post-medieval adolescent of known age and sex

Developmental disturbances that affect the secretion of enamel matrix can cause defective enamel structure. Linear hypoplasia is one type of enamel defect and manifests itself as a furrow that runs around the circumference of the tooth. Such defects range in size from the microscopic to those that are several millimetres wide. Enamel defects have been widely used by anthropologists for the investigation of growth disruptions in past populations, as they provide a permanent record of disturbances during much of a child's developmental period. This is a detailed case study of enamel growth disruptions in a 15-year-old female from the 18th and 19th century crypt of Christ Church, Spitalfields. The method used relates linear enamel hypoplasia to the incremental structures in the enamel surface, the perikymata, in order to investigate the timing of growth disturbances. Linear enamel hypoplasia was defined here as a greater than expected spacing between neighbouring pairs of perikymata. In addition, this study used recently published histological data on the precise timing of tooth development to establish chronologies for growth disruptions. Defects were matched in at least two teeth with overlapping developmental schedules to ensure that systemic disturbances, as opposed to localised traumas, were identified. Thirteen enamel defects were matched between five different teeth from the same individual from Spitalfields. Most linear enamel hypoplasias were evident on the anterior dentition. Using an 8-day average perikymata periodicity, the age at first defect in this individual was calculated as 1.5 years and the last growth disruption occurred when she was 4.6 years of age. The distribution of the defects was examined to identify any seasonal pattern in the occurrence of the growth disturbances.

Well-being changes in response to 30 years of regional integration in Maya populations from Yucatan, Mexico

Infant mortality rate (IMR), overall frequency of linear enamel hypoplasia (LEH), sexual dimorphism in LEH, age of onset of LEH, and age at menarche were used as indicators to test the hypothesis that the origin and development of the tourist industry and increased state participation on Maya subsistence agriculturists in the early 1970s had improved the well-being of the Maya. Two historical moments where inferred from the data. The first was derived from cheap and effective immunization and sanitation campaigns that reduced IMR from 143.4/1,000 live births in the early 1960s to 97.4 in the early 1970s. State participation broke the undernutrition-disease cycle enough to reduce LEH frequencies significantly (from 71.9% in individuals born before 1971 to 51.5% in those born in 1971 or after, chi(2) = 55.72; 1 df; alpha = 0.00001) and to eliminate the sex difference in LEH expression (from a 14.8% LEH difference between men and women before 1971 [Male/Female Odds Radio = 0.45, alpha significant at 0.05] to a nonsignificant 2% difference). Improvement in overall living conditions reflected in a "modern stage" infant mortality regime and an almost disappearance of LEHs, resulted from gradual improvements in living conditions that did not become apparent until the 1980s. Trends in the age at menarche are not statistically significant, probably due to methodological limitations. However, if overall living conditions continue to improve or stay as they are today, accelerations in maturation should become noticeable.

Interpreting sex differences in enamel hypoplasia in human and non-human primates: Developmental, environmental, and cultural considerations

The purpose of this review is to provide a synoptic, critical evaluation of the evidence of, and potential etiological factors contributing to, sex differences in the expression of enamel hypoplasia (EH). Specifically, this review considers theoretical expectations and empirical evidence bearing on two central issues. The first of these is the impact of a theorized inherent male vulnerability to physiological stress on sex differences in EH. The second issue is the potential contribution to sex differences in EH of intrinsic differences in male and female enamel composition and development. To address this first issue, EH frequencies by sex are examined in samples subject to a high degree of physiological stress. Based on the concept of inherent male vulnerability (or female buffering), males in stressful environments would be expected to exhibit higher EH frequencies than females. This expectation is evaluated in light of cultural practices of sex-biased investment that mediate the relationship between environmental stress and EH expression. Defects forming prenatally afford an opportunity to study this relationship without the confounding effects of sex-biased postnatal investment. Data bearing on this issue derive from previously conducted studies of EH in permanent and deciduous teeth in both modern and archaeological samples as well as from new data on Indian schoolchildren. To address the second issue, fundamental male-female enamel differences are evaluated for their potential impact on EH expression. A large sex difference in the duration of canine crown formation in non-human primates suggests that male canines may have greater opportunity to record stress events than those of females. This expectation is examined in great apes, whose canines often record multiple episodes of stress and are sexually dimorphic in crown formation times. With respect to the first issue, in most studies, sex differences in EH prevalence are statistically nonsignificant. However, when sex differences are significant, there is a slight trend for them to be greater in males than in females, suggesting a weak influence of greater male vulnerability. Cultural practices of sex-biased investment in children appear to have greater impact on EH expression than does male vulnerability/female buffering. With respect to the second issue, sex differences in the composition and development of enamel were reviewed and determined to have limited or unknown impact on EH expression. Of these factors, only the duration of crown formation was expected to affect EH expression by sex within the great apes. The data support an association between higher defect counts in the canines of great ape males relative to those of females that may be the result of longer crown formation times in the canines of great ape males. This review concludes with an assessment of the nature of the evidence currently available to examine these issues and suggests future avenues for research focused on elucidating them.