Patterns of growth and development of the human skeleton and dentition in relation to environmental quality: A biocultural analysis of a sample of 20th century Portuguese subadult -documented skeletons

A basic assumption in human osteological research is that dental development is less influenced by environmental insults than skeletal development and thus considered the best indicator of chronological age in human skeletal remains from archaeological populations and forensic contexts, while skeletal development is more affected and thus provides a measure of growth faltering and health differentials between archaeological populations. The subadult skeletal sample of the identified collection of human skeletons at the Bocage Museum (National Museum of Natural History) offers the unique opportunity to test such a fundamental preposition by analysing the pattern of skeletal and dental development in two sub-samples that differ in their exposure to environmental insults. Information such as occupation of the father and address were used as indicators of socioeconomic status, a basic measure of environmental quality. Skeletal development was expressed as long bone length and as the attainment of levels of growth completion in long bone length. Dental development was expressed as growth in tooth length and as the attainment of levels of tooth formation. Comparisons based on socioeconomic status reveal that both skeletal and dental systems tend to be delayed in low socioeconomic groups but skeletal development is much more affected. Growth of the long bones tends to be very delayed, particularly the lower limb. No differences in skeletal maturation were detected between socioeconomic groups. Socioeconomic differences in dental development are nonexistent or small and tend to be more evident when expressed as levels of attainment of stages of tooth formation compared to tooth length. Cause of death was also found to be an important confounder since individuals that died of chronic conditions tend to be more delayed and thus be wrongly classified as low socioeconomic status. Surprisingly, girls of low socioeconomic status are more skeletally delayed than boys. The results indicate that skeletal development is almost never a good indicator of chronological age, except for observations of skeletal maturation in the adolescent period. Tooth formation, on the other hand, shows a better correlation with chronological age and dental linear growth provides the best overall estimates. However, dental development may overestimate age considerably at the lower extreme of the socioeconomic gradient.