An analysis of secular change in the human mandible over the last century
Article first published online: 14 JUL 2009
Copyright © 2009 Wiley-Liss, Inc.
American Journal of Human Biology
Special Issue: Special Section: Symposium in Honor of A. Roberto Frisancho
Volume 21, Issue 5, pages 704–706, September/October 2009
How to Cite
Martin, D. C. and Danforth, M. E. (2009), An analysis of secular change in the human mandible over the last century. Am. J. Hum. Biol., 21: 704–706. doi: 10.1002/ajhb.20866
- Issue published online: 3 AUG 2009
- Article first published online: 14 JUL 2009
- Manuscript Accepted: 17 NOV 2008
- Manuscript Received: 24 OCT 2008
In light of several recent investigations that have identified notable secular change in cranial size and morphology over the last century, the present study addresses its possible effects in the mandible in U.S. populations. Standard measurements of 407 mandibles from the Terry (Smithsonian) and Hamann-Todd (Cleveland Museum of Natural History) Collections, which are primarily composed of individuals living in the early 20th century, were compared with those of 595 mandibles from the Forensic Anthropology Database (Tennessee), which is primarily composed of individuals living from the later part of the century. The t-tests between the two temporally-different samples by sex and race showed statistically significant decreases in mandibular body width and bigonial breadth as well as significant increases in mandibular body length in nearly all subgroups. White males showed the greatest amount of change, and Black females, the least. Overall, these findings support the conclusion that the mandible is transforming into a longer, narrower, more gracile bone, paralleling many of the morphological shifts seen in the cranium. Factors involved likely include changes in diet, medical care, and dental practices. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc.