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

Abstract

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.

Dental diseases of human skeletal remains from the early-modern period of Kumejima Island, Okinawa, Japan

“…King et al (2005) revealed that younger individuals of a skeletal series, or individuals who died earlier in life, had an earlier first incidence of LEH than the older individuals. Although we examined the relationship between the first occurrence of LEH and individual ages in the Kumejima series, no positive correlations were found; however, the fact that the younger and female individuals tended to be more affected in the Kumejima series indicates that females (when they were children) experienced greater physiological stress than males, and that individuals that died younger tended to have been exposed to greater stress during childhood, as reported in the medieval Danish village of Tirup (Boldsen, 2007).…”

“…Because ameloblasts are lost with tooth eruption, enamel is not capable of further growth or remodeling, i.e. LEH provides a means by which growth disturbance during early childhood can be examined from the permanent teeth of adults (King et al, 2005). Therefore, many authors have investigated the prevalence and timing of LEH in a range of prehistoric cranial series (e.g.…”

Caries Through Time: An Anthropological Overview

“…However, women usually show more severe nutritional stress markers, such as frequent enamel hypoplasias, less intervals between defects and more frequent tooth growth disruptions (King et al, 2005).…”

Sex differences in linear enamel hypoplasia (LEH) in early modern Japan

“…However, an investigation of sex differences in LEH for a particular period in Japan has not previously been reported. Research in other countries has produced contradictory results: higher prevalence in males (Van Gerven, et al, 1990;Saunders and Keenleyside, 1999;Palubeckaite, et al, 2002), higher prevalence in females (May et al, 1993;Slaus, 2000;King, et al, 2005), and no significant differences between the sexes (Goodman et al, 1980;Lanphear, 1990;Duray, 1996;Malville, 1997;Lovell and Whyte, 1999;Slaus, 2008).…”