Assessment of physiological disturbances during pre- and early postnatal development based on microscopic analysis of human deciduous teeth from the Late Epipaleolithic site of Shubayqa 1 (Jordan).

OBJECTIVES: To study pre- and early postnatal tooth formation and to analyze the effects of physiological disturbances on enamel and dentin formation in deciduous teeth of infants from the Late Epipaleolithic (Natufian) site Shubayqa 1. MATERIALS AND METHODS: Ten deciduous teeth from six infants (ages at death between 21 and 239 days) were analyzed by light and scanning electron microscopy. RESULTS: Marked prism cross-striations and an abnormal wavy course of the prisms were recorded in pre- and postnatal enamel of all analyzed teeth. Single or multiple accentuated incremental lines were observed in prenatal enamel of nine teeth and in postnatal enamel of eight teeth. Accentuated Andresen lines and broader zones exhibiting an enhanced calcospheritic pattern were recorded in the pre- and postnatally formed dentin of nine teeth. DISCUSSION: The structural abnormalities in the pre- and postnatally formed enamel of the infants are considered indicative of chronic stress that negatively affected the activity of secretory ameloblasts. The structural aberrations in pre- and postnatal dentin denote that odontoblasts were also affected by this stress. The presence of single or multiple accentuated incremental lines in pre- and postnatal enamel is interpreted as reflecting (short-term) impacts of higher intensity superimposed on the chronic stress. Our findings suggest compromised maternal health affecting the late fetus and compromised health in newborns. Although limited by the small number of analyzed individuals, the present study contributes to the knowledge of maternal and early infant health conditions in Late Epipaleolithic populations.

Cross-sectional analysis of long bones, occupational activities and long-distance trade of the Classic Maya from Xcambó--archaeological and osteological evidence.

Xcambó is a Classic period Maya site (250-700 AD) situated on the northern coast of Yucatan, Mexico. Archaeological evidence suggests that the site began as a salt production center but adopted a more administrative role as a commercial port in the Late Classic period. Economic growth, depending on its magnitude, could have affected the daily occupations of Xcambó's inhabitants. However, this is difficult to infer from the archaeological record. The aim of this study was to directly evaluate this possibility through skeletal analysis. Since diaphyseal robusticity and shape are predominantly influenced by mechanical loading history, long bone cross-sections can be used to access activity patterns. To this end, humeri and femora of 47 male and 35 female adult specimens from two Xcambó population samples were scrutinized. Our analysis satisfies general archaeological expectations and provides additional information on the population's physical response to economic growth. Decreasing robusticity and femoral anterior-posterior rigidity indicate an overall decrease in physical workload and mobility, concomitant with the site's increasing administrative function. We also observed a significant decrease in sexual dimorphism, possibly attributable to the differential response of male and female physical work spheres during socioeconomic change. In general, our findings suggest even nonsubsistence based socioeconomic change can significantly affect the bone structure of a population, rendering activity analysis an important aspect of the reconstruction of living conditions of past populations.