Severe developmental defects of enamel in a human skeleton of the Final Jomon age from the Nakazawahama shell-mound, Iwate, Japan

In an adult human skeleton of the Final Jomon age excavated at the Nakazawahama shell-mound in Iwate Prefecture, northeastern Japan, grooved enamel defects (about 2 mm in width) were observed circumferentially around the dental crowns of the upper left central incisor, upper right lateral incisor, and upper right canine. Observations of the crown surface using a stereomicroscope and evaluations of soft X-ray images revealed severe developmental defects of enamel (DDEs), having the characteristics of both enamel hypoplasia and enamel hypocalcification caused by systemic metabolic stresses. We estimated that these defects were formed at the age of late 1 year. This is the first report on such severe enamel defects in a Jomon skeleton.