Biomechanics of the rostrum and the role of facial sutures
Version of Record online: 20 MAR 2003
Copyright © 2003 Wiley-Liss, Inc.
Journal of Morphology
Volume 257, Issue 1, pages 33–44, July 2003
How to Cite
Rafferty, K. L., Herring, S. W. and Marshall, C. D. (2003), Biomechanics of the rostrum and the role of facial sutures. J. Morphol., 257: 33–44. doi: 10.1002/jmor.10104
- Issue online: 20 MAR 2003
- Version of Record online: 20 MAR 2003
- National Institute of Dental Research. Grant Number: PHS DE08513
- craniofacial suture;
- facial bones;
- bone strain
The rostrum is a large diameter, thin-walled tubular structure that receives loads from the teeth. The rostrum can be conceptualized both as a rigid structure and as an assemblage of several bones that interface at sutures. Using miniature pigs, we measured in vivo strains in rostral bones and sutures to gain a better understanding of how the rostrum behaves biomechanically. Strains in the premaxillary and nasal bones were low but the adjacent maxillary-premaxillary, internasal, and intermaxillary suture strains were larger by an order of magnitude. While this finding emphasizes the composite nature of the rostrum, we also found evidence in the maxillary and nasal bones for rigid structural behavior. Namely, maxillary strain is consistent with a short beam model under shear deformation from molar loading. Strain in the nasal bones is only partially supported by a long beam model; rather, a complex pattern of dorsal bending of the rostrum from incisor contact and lateral compression is suggested. Torsion of the maxilla is ruled out due to the bilateral occlusion of pigs and the similar working and balancing side strains, although it may be important in mammals with a unilateral bite. Torsional loading does appear important in the premaxillae, which demonstrate working and balancing side changes in strain orientation. These differences are attributed to asymmetrical incisor contact occurring at the end of the power stroke. J. Morphol. 257:33–44, 2003. © 2003 Wiley-Liss, Inc.