No relationship found between dental fluctuating asymmetry, birthweight, and birth term in two modern North American samples.

OBJECTIVE: Deciduous dental crowns primarily develop during gestation and early infancy and embody early life stress exposures. Composite measures of dental fluctuating asymmetry (DFA) generated from the deciduous teeth may therefore indicate cumulative gestational stress in developmental origins of health and disease (DOHaD) studies. This study examines whether higher composite measures of deciduous DFA are associated with low birthweight and prematurity, two aspects of birth phenotype consistently associated with increased morbidity and mortality risks in adulthood. SUBJECTS AND METHODS: We evaluated associations between composite deciduous DFA, birthweight, and birth term in two contemporary North American samples: an autopsy sample from New Mexico (n = 94), and sample from a growth cohort study in Burlington, Ontario (n = 304). Dental metric data for each sample was collected from postmortem CT scans and dental casts, respectively. Composite DFA was estimated using buccolingual (BL) and mesiodistal (MD) crown diameters from paired deciduous teeth. RESULTS: Contrary to expectations, the results of linear regression indicated no significant relationship between birthweight and DFA, or birth term and DFA, in either sample. CONCLUSIONS: Deciduous DFA does not predict aspects of birth phenotype associated with gestational stress. Birthweight and birth term are plastic relative to the more developmentally stable deciduous dentition, which may only subtly embody early life stress. We suggest that deciduous DFA should be utilized with caution in DOHaD studies until its relationship with gestational stress is clarified.

Biocultural and social determinants of ill health and early mortality in a New Mexican paediatric autopsy sample.

RESULTS.: Hispanic children have higher odds of growth stunting than non-Hispanic White children. Native American children die younger and have higher odds of respiratory diseases and porous lesions than Hispanic and non-Hispanic Whites. Rural/urban location does not significantly impact age at death, but housing type does. Individuals who lived in trailers/mobile homes had earlier ages at death. When intersections between housing type and housing location are considered, children who were poor and from impoverished areas lived longer than those who were poor from relatively well-off areas. CONCLUSIONS.: Children's health is shaped by factors outside their control. The children included in this study embodied experiences of social and ELS and did not survive to adulthood. They provide the most sobering example of the harm that social factors (structural racism/discrimination, socioeconomic, and political structures) can inflict.

Low bone mineral density is associated with fatty liver disease and respiratory illness in a pediatric mortality sample.

This study finds that fatty liver disease is associated with low bone density in a pediatric mortality sample. Since non-alcoholic fatty liver disease has increased in prevalence over the past few decades among children, a better understanding of the disease's impacts on bone health is of significance to clinicians. PURPOSE: Chronic illness leads to decreased bone modeling and remodeling. This can be especially problematic during childhood and adolescence, since the majority of an individual's peak bone mass is achieved by the age of 20. In this study, we examine relationships between chronic illness and low bone mineral density (BMD) in a pediatric mortality sample (aged 0.5 to 20.9 years) from New Mexico. We also test whether low BMD is related to decelerated linear growth by examining its relationship to growth stunting and arrest (Harris lines). METHODS: Hounsfield units (HU), a proxy for trabecular BMD, were obtained at the fourth lumbar vertebra and the femoral neck from postmortem CT scans. Linear regression was used to examine associations between z-standardized HU and age, sex, medical conditions, Harris lines, and growth stunting. RESULTS: We find that lumbar HU is significantly lower for individuals with fatty liver disease and respiratory illness; femoral HU is significantly lower in individuals with Harris lines. CONCLUSION: The mechanisms of low BMD in individuals with fatty liver disease and respiratory illness are likely multifactorial and involve vitamin D deficiency (malnutrition, malabsorption), systemic inflammation, and sedentary lifestyles. However, better awareness of this relationship can provide clinicians with the ability to introduce nutritional and behavioral interventions early to mitigate deleterious effects on bone. Harris lines, on the other hand, mark temporary growth cessation due to physiological stress followed by a rapid resumption of growth. Low BMD in these individuals may be due to bone mineralization lagging behind relatively rapid linear growth.

Perinatal Disorders and Small Birthweight Are Significantly Associated With Small Vertebral Neural Canal Size in a Contemporary Pediatric Autopsy Sample.

STUDY DESIGN: A retrospective, nonblinded, single-center observational study. OBJECTIVE: The purpose of this study is to examine associations between small vertebral neural canal (VNC) measurements with verified experiences of early-life stress (ELS) (premature birth, disorders or conditions arising in the perinatal period, and congenital disorders) in a pediatric autopsy sample, paired with other skeletal indicators of stress, and known demographic/health information. SUMMARY OF BACKGROUND DATA: Most studies linking small VNC size to ELS are for human remains from archeological sites without known demographic information or health history, making it difficult to assess what kind of stress might affect VNC growth. METHODS: This is a single-center retrospective study in a pediatric autopsy sample of 623 individuals (aged 0.5 to 20.9 yr) with known sex, age, and manner of death (MOD), who died between 2011 and 2019. Data were collected from postmortem computed tomography scans, autopsy, and field investigator reports. Data include VNC anteroposterior and transverse (TR) diameters of the 12th thoracic (T12) and fifth lumbar (L5) vertebrae, bone mineral density, and Harris lines. RESULTS: Small birthweight males have significantly smaller VNC than those with an average birthweight. The natural MOD is associated with smaller VNC. Perinatal disorders and growth stunting are associated with smaller T12 anteroposterior, T12-TR, and L5-TR diameters. Congenital disorders and Harris lines are not associated with small VNC. CONCLUSIONS: Reduced VNC size is a reliable indicator of severe ELS, but not all ELS leads to reduced VNC. Females appear less susceptible to perinatal environmental stress than males. Reduced VNC may also be indicative of heightened risk of disease and death in those who died of natural MOD. LEVEL OF EVIDENCE: Level 2.

Skeletal manifestations of disease experience: Length of illness and porous cranial lesion formation in a contemporary juvenile mortality sample.

OBJECTIVES: Porous lesions of the orbit (cribra orbitalia [CO]) and cranial vault (porotic hyperostosis [PH]) are used as skeletal indicators of childhood stress. Because they are understudied in contemporary populations, their relationship to disease experience is poorly understood. This paper examines the relationship between length of childhood illness and CO/PH formation in a clinically documented sample. "Turning points," which identify the window for lesion formation for CO/PH, are defined, implications for hidden heterogeneity in frailty are considered. METHODS: Data are from 333 (199 males; 134 females) pediatric postmortem computed tomography scans. Individuals died in New Mexico (2011-2019) and are 0.5 to 15.99 years (mean = 7.1). Length of illness was estimated using information from autopsy and field reports. Logistic regression was used to estimate predicted probabilities, odds ratios, and the temporal window for lesion formation. RESULTS: Illness, single bouts, or cumulative episodes lasting over 1 month is associated with higher odds of CO; individuals who were never sick have lower odds of having PH. This relationship was consistent for fatal and incidental illnesses that did not cause death. The developmental window for CO formation appears to close at 8 years. CONCLUSIONS: Those ill for over 1 month are more likely to have CO/PH than those with acute illnesses. Some individuals lived sufficiently long to form CO/PH but died of illness. Others with lesions died of circumstances unrelated to disease. This indicates hidden variation in robusticity even among ill individuals with CO/PH, which is vital in interpreting lesion frequencies in the archeological record.

South-to-north migration preceded the advent of intensive farming in the Maya region.

The genetic prehistory of human populations in Central America is largely unexplored leaving an important gap in our knowledge of the global expansion of humans. We report genome-wide ancient DNA data for a transect of twenty individuals from two Belize rock-shelters dating between 9,600-3,700 calibrated radiocarbon years before present (cal. BP). The oldest individuals (9,600-7,300 cal. BP) descend from an Early Holocene Native American lineage with only distant relatedness to present-day Mesoamericans, including Mayan-speaking populations. After ~5,600 cal. BP a previously unknown human dispersal from the south made a major demographic impact on the region, contributing more than 50% of the ancestry of all later individuals. This new ancestry derived from a source related to present-day Chibchan speakers living from Costa Rica to Colombia. Its arrival corresponds to the first clear evidence for forest clearing and maize horticulture in what later became the Maya region.

A biological approach to adult sex differences in skeletal indicators of childhood stress.

OBJECTIVES: In previous work examining the etiology of cribra orbitalia (CO) and porotic hyperostosis (PH) in a contemporary juvenile mortality sample, we noted that males had higher odds of having CO lesions than females. Here, we examine potential reasons for this pattern in greater detail. Four non-mutually exclusive mechanisms could explain the observed sex differences: (1) sex-biased mortality; (2) sexual dimorphism in immune responses; (3) sexual dimorphism in bone turnover; or (4) sexual dimorphism in marrow conversion. SUBJECTS AND METHODS: The sample consists of postmortem computed tomography scans and autopsy reports, field reports, and limited medical records of 488 individuals from New Mexico (203 females; 285 males) aged between 0.5 and 15 years. We used Kaplan-Meier survival analysis, predicted probabilities, and odds ratios to test each mechanism. RESULTS: Males do not have lower survival probabilities than females, and we find no indications of sex differences in immune response. Overall, males have a higher probability of having CO or PH lesions than females. CONCLUSIONS: All results indicate that lesion formation in juveniles is influenced by some combination of sex differences in the pace of red-yellow conversion of the bone marrow and bone turnover. The preponderance of males with CO and PH likely speaks to the potential for heightened osteoblastic activity in males. We find no support for the hypotheses that sex biases in mortality or immune responses impacted lesion frequency in this sample. Sex differences in biological processes experienced by children may affect lesion formation and lesion expression in later life.

Do computed tomography findings agree with traditional osteological examination? The case of porous cranial lesions.

OBJECTIVE: The current study evaluates the feasibility of using clinical cranial computed tomography (CT) scans for assessing the presence and morphology of porous cranial lesions (cribra orbitalia, porotic hyperostosis). METHODS: Observers (n = 4) conducted three independent evaluations of porous cranial lesions based on photographs, 2-D CT, and 3-D CT scans of archaeological crania. Evaluations of the crania from each viewing scenario were compared to findings from direct macroscopic observation. MATERIALS: Twenty-two complete adult crania from the Peruvian sites of Pachacamac and Chicama. RESULTS: We found that lesion visibility differed by location: vault lesions with porosity larger than the resolution of the CT scan were identifiable across all viewing scenarios, but orbital lesions were identifiable only when extensive porosity was accompanied by widening of the inter-trabecular spaces. Lesions in stages of advanced remodeling were not visible on CT. CONCLUSIONS: Paleopathological criteria applied to head CTs from clinical cases of suspected cranial fracture can reliably identify moderate to severe porous cranial lesions in living individuals. SIGNIFICANCE: This validation study opens the door to broader study of porous cranial lesions in living individuals that can address open questions about the causes and consequences of these commonly reported skeletal indicators of stress. LIMITATIONS: Performance of all viewing scenarios was evaluated relative to assessment data from direct observation of skeletal remains, but direct observation is itself subject to error. SUGGESTIONS FOR FURTHER RESEARCH: The increasing resolution of routine CTs makes it increasingly possible to explore skeletal lesions in clinical contexts.

Increased dental fluctuating asymmetry is associated with active skeletal lesions, but not mortality hazards in the precontact Southwest United States.

OBJECTIVE: This study examines whether individuals with higher dental fluctuating asymmetry (DFA) are frailer than those with lower DFA, by examining whether increased DFA is associated with skeletal lesion formation. SUBJECTS AND METHODS: 150 individuals with permanent teeth and 64 individuals with deciduous teeth. All individuals are Ancestral Puebloans from archaeological sites in modern-day New Mexico. We estimate DFA in three ways: (a) deciduous DFA only, (b) permanent DFA only, and (c) a composite of permanent and deciduous DFA. We analyzed DFA alongside lesion status for cribra orbitalia (CO) and porotic hyperostosis (PH), as well as the presence/absence of enamel hypoplasia (EH). All stress indicators were further analyzed for their impact on mortality hazards. RESULTS: We find that individuals with active CO and PH lesions have increased DFA, while those with healed lesions have lower DFA. We found no relationship between EH and DFA. Further, DFA alone does not predict individual mortality but CO does. CONCLUSIONS: Individuals with increased DFA are frailer and therefore, less capable of buffering themselves against perturbations to their health than those with lower DFA. All results indicate that individuals in this study with lower DFA were more successful in buffering themselves against random environmental impacts during childhood. While DFA alone does not predict mortality hazard, its relationship to lesion status (lower DFA in individuals with healed lesions) indicates that it would be a valuable addition to studies of health and stress.

Cribra orbitalia and porotic hyperostosis are associated with respiratory infections in a contemporary mortality sample from New Mexico.

OBJECTIVES: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs) classically associated with iron-deficiency anemia in bioarchaeological contexts. However, recent studies indicate a need to reassess the interpretation of PCLs. This study addresses the potential health correlates of PCLs in a contemporary sample by examining relationships between the known cause of death (COD) and PCL presence/absence. METHODS: This study includes a sample of 461 juvenile individuals (6 months to 15 years of age) who underwent examination at the University of New Mexico's Office of the Medical Investigator between 2011 and 2019. The information available for each individual includes their sex, age at death, and their COD and manner of death. RESULTS: Odds ratio of having CO (OR = 3.92, p < .01) or PH (OR = 2.86, p = .02) lesions are increased in individuals with respiratory infections. Individuals with heart conditions have increased odds of having CO (OR = 3.52, p = .03) lesions, but not PH. CONCLUSION: Individuals with respiratory infection are more likely to have CO and/or PH. CO appears to have a greater range of health correlates than PH does, as indicated by the heart condition results. However, individuals with congenital heart defects are at higher risk for respiratory infections, so bony alterations in cases of heart conditions may be due to respiratory illness. Since respiratory infection remains a leading cause of mortality today, CO and PH in bioarchaeological contexts should be considered as potential indicators of respiratory infections in the past.

Early isotopic evidence for maize as a staple grain in the Americas.

Maize is a cultigen of global economic importance, but when it first became a staple grain in the Americas, was unknown and contested. Here, we report direct isotopic dietary evidence from 52 radiocarbon-dated human skeletons from two remarkably well-preserved rock-shelter contexts in the Maya Mountains of Belize spanning the past 10,000 years. Individuals dating before ~4700 calendar years before present (cal B.P.) show no clear evidence for the consumption of maize. Evidence for substantial maize consumption (~30% of total diet) appears in some individuals between 4700 and 4000 cal B.P. Isotopic evidence after 4000 cal B.P. indicates that maize became a persistently used staple grain comparable in dietary significance to later maize agriculturalists in the region (>70% of total diet). These data provide the earliest definitive evidence for maize as a staple grain in the Americas.

Sociocultural determinants of health and wealth in historic African Americans.

In this study, we examine the impacts of individual ancestry and socioeconomic status (SES) on health in historic African Americans through bioarchaeological means. We estimate ancestry from dental morphology and SES from the costs of coffin hardware. We include 188 adult individuals from Freedman's Cemetery in Dallas, Texas, and 2,301 individuals of African and European descent for comparison. Freedman's Cemetery functioned as the only cemetery available to freed people and their descendants between 1869 and 1907. Linear discriminant analysis (LDA) of dental morphological traits was used to estimate individual ancestry. LDA results were then used in Cox proportional hazards analysis to examine whether ancestry impacted mortality risk or SES. Ancestry was not found to impact SES. However, paralleling results from analysis of census mortality data, individuals with greater African ancestry on average have shorter lifespans and higher mortality hazards than individuals who have more European ancestry. This finding provides evidence for structural violence in this historic African American skeletal sample. The negative effects of social constructs are embodied and can be detected in skeletal samples through use of statistical methods combined with information about the cultural context in which people lived.

Indicators of stress and their association with frailty in the precontact Southwestern United States.

OBJECTIVES: Physiological disturbances in early life have been shown to increase individual mortality risk and impact health in adulthood. This study examines frailty through analysis of lesion status of two commonly collected skeletal indicators of stress (cribra orbitalia [CO] and porotic hyperostosis [PH]) and their association with mortality risk in the precontact U.S. Southwest. Several predictions are addressed: (a) individuals with active skeletal lesions are the frailest; (b) individuals with healed lesions are the least frail; (c) CO lesions, regardless of status, are associated with increased mortality risk. MATERIALS AND METHODS: Odds ratios and Kaplan-Meier survival analysis are used to examine the association between stress indicators and mortality in the U.S. Southwest. This study includes 335 individuals (75 females, 81 males, 20 adults of unknown sex, and 159 juveniles) from precontact New Mexico archaeological sites dating to A.D. 1,000-1,400. RESULTS: Active CO and PH lesions are associated with lower survivorship and greater mortality risk than healed or absent lesions. Only juvenile individuals have active CO and PH lesions, as is expected given their physiology. CO lesions in any state are associated with greater mortality risk and earlier ages of death. DISCUSSION: Individuals with active lesions are the frailest; while individuals with healed lesions are the least frail. CO and PH likely have different etiologies: CO lesions are associated with increased mortality risk and decreased individual longevity. These results indicate that CO's presence suggests a more severe underlying condition than PH lesions alone.