The 81st Annual Meeting of the American Association of Physical Anthropologists (2012)

Reconstruction of systemic stress using incremental microstructures of enamel in an individual from the Late/Final Jomon period, Japan


1Anthropology, University of North Carolina Wilmington, 2Physical Anthropology, University of Kyoto

Thursday 10:45-11:00, Broadway III/IV Add to calendar

This study reconstructs systemic stress patterning using incremental microstructures of enamel in a subadult from the Yoshigo cemetery (3200 through 2800 BP), Aichi Prefecture, Japan. High resolution impressions and replicas were collected for each anterior tooth. Each replica was studied under 50, 100, or 200x magnification on a measuring microscope. Distances between perikymata grooves and from the lens to the objective were recorded using specialized software. LEH defects were identified as accentuated spacing in perikymata combined with a depression in the enamel surface and were chronologically matched across the dentition. Each defect was placed within a chronological sequence based on decile location and distance from the cemento-enamel junction. Stress duration was estimated by counting the perikymata in the occlusal wall of each defect and multiplying that value by the modal periodicity for striae formation. Percentage of enamel growth disruption was estimated by dividing the number of perikymata within the occlusal wall of each matched defect by the total number of perikymata within the imbricational enamel. Eight LEH defects were chronologically matched. Chronology of matched LEH defects ranged between 1.2 through 3.5 and 0.1 through 3.7 years of age when using the decile and height methods respectively. Number of perikymata located within the occlusal wall of each defect ranged from one through 20. Estimated durations of stress ranged from eight through 120 days. Disrupted enamel growth ranged from 8.1% in the maxillary left canine to 50.7% in the maxillary right central incisor.

National Science Foundation (BCS 1044950), Japan Society for the Promotion of Science (07012)

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