AbstractThis paper examines the prevalence of Wilson bands and hypoplasias in the dental enamel of a sample of Postclassic and Historic Maya Indian remains from the archaeological site of Lamanai, Belize. Mandibular canines were removed from 23 individuals from the two periods. The surface of a polished, acid etched, longitudinal section of each canine was examined with scanning electron microscopy for the presence of enamel malformations.A large number of Wilson bands and shallow hypoplasias were identified; however, more severe macroscopic hypoplasias were rare. The two kinds of defects were found to be temporally associated in only 25–50% of instances, indicating that circumstances leading to their formation are likely distinct.The mean number of both Wilson bands and shallow hypoplasias was found to be significantly different between samples, indicating an increase in developmental stress in the Historic occupation. As dietary differences have not been detected between the occupations, the observed differences in enamel defect prevalence can be attributed to the effects of changing epidemiological patterns following the Spanish conques