Enamel Hypoplasia in the Deciduous Teeth of Edo Japanese

Enamel hypoplasia is a reduction in enamel thickness caused by a variety of nutritional deficiencies or systemic diseases which occur during tooth formation. Enamel hypoplasia in the deciduous teeth is considered as a valuable indicator of stress. Its frequency, time of occurrence, and association with cribra orbitalia were examined on 62 immature skulls from the Hitotsubashi Metropolitan High School Site (ca. 17th century), Tokyo, Japan. Of 42 observed individuals, 7 (16.7%) had enamel hypoplasia in the deciduous teeth. Most of the enamel hypoplasia detected occurred postnatally, few occurring prenatally and perinatally. The highest frequency was found on the deciduous maxillary central incisors (21.1%). These results suggest that people in Edo City lived under highly stressful environment.