Reduced stiffness of alveolar bone in the colobine mandible
Article first published online: 10 NOV 2010
Copyright © 2010 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 144, Issue 3, pages 421–431, March 2011
How to Cite
Daegling, D. J., Granatosky, M. C., McGraw, W. S. and Rapoff, A. J. (2011), Reduced stiffness of alveolar bone in the colobine mandible. Am. J. Phys. Anthropol., 144: 421–431. doi: 10.1002/ajpa.21423
- Issue published online: 7 FEB 2011
- Article first published online: 10 NOV 2010
- Manuscript Accepted: 14 SEP 2010
- Manuscript Received: 22 MAR 2010
- NSF. Grant Numbers: BCS-922429, 60017683, 0921770, 0922414
- Yerkes National Primate Research Centers
- Conservation International
Alveolar bone has several mechanical functions, including tooth support and accommodation of occlusal and other masticatory forces. Its unique functional-mechanical environment is reflected by its structural characteristics, but whether alveolar bone is materially distinct from bone elsewhere in the primate facial skeleton is uncertain. This uncertainty is attributable not only to a limited amount of data but also to conflicting findings among these data. We evaluated elastic modulus variation in the mandibular corpus of eight adult specimens of the monkeys Procolobus badius and Colobus polykomos via microindentation to evaluate whether alveolar bone is more compliant than basal bone and to quantify patterns of variation between sexes and species. We sampled Vickers hardness from six serial transverse sections and one coronal section from both the alveolar process and the basal corpus. Hardness values were converted to elastic modulus via regressions specific for bone tissue. Analysis of variance reveals that a plurality of variation is found on a regional scale; i.e., alveolar bone is more compliant than adjacent basal bone. Species affiliation and sex are not significant sources of variation. These findings support a hypothesis that compliance of alveolar bone represents a material solution for avoiding large stress concentrations arising from occlusal loads. Other comparative data suggest important differences between colobine and cercopithecine mandibles in terms of bone stiffness, both overall and in terms of relative stiffness of alveolar and basal cortical bone. Am J Phys Anthropol, 2011. © 2010 Wiley-Liss, Inc.