title: Elastic Properties of Chimpanzee Craniofacial Cortical Bone.
abstract: Relatively few assessments of cranial biomechanics formally take into account variation in the material properties of cranial cortical bone. Our aim was to characterize the elastic properties of chimpanzee craniofacial cortical bone and compare these to the elastic properties of dentate human craniofacial cortical bone. From seven cranial regions, 27 cylindrical samples were harvested from each of five chimpanzee crania. Assuming orthotropy, axes of maximum stiffness in the plane of the cortical plate were derived using modified equations of Hooke's law in a Mathcad program. Consistent orientations among individuals were observed in the zygomatic arch and alveolus. The density of cortical bone showed significant regional variation (P < 0.001). The elastic moduli demonstrated significant differences between sites, and a distinct pattern where E3> E2> E1. Shear moduli were significantly different among regions (P < 0.001). The pattern by which chimpanzee cranial cortical bone varies in elastic properties resembled that seen in humans, perhaps suggesting that the elastic properties of craniofacial bone in fossil hominins can be estimated with at least some degree of confidence. Anat Rec, 299:1718-1733, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas.
authors.forename: Poorva
authors.initials: P
authors.lastname: Gharpure
authors.affiliation: Department of Restorative Dentistry, Texas A&M University College of Dentistry, Dallas, Texas.
authors.forename: Elias D
authors.initials: ED
authors.lastname: Kontogiorgos
authors.affiliation: Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas.
authors.forename: Lynne A
authors.initials: LA
authors.lastname: Opperman
authors.affiliation: Department of Organismal Biology & Anatomy, University of Chicago, 1027 East 57th Street, Chicago, Illinois.
authors.forename: Callum F
authors.initials: CF
authors.lastname: Ross
authors.affiliation: Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri.
authors.forename: David S
authors.initials: DS
authors.lastname: Strait
authors.affiliation: Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri.
authors.forename: Amanda
authors.initials: A
authors.lastname: Smith
authors.affiliation: Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas.
authors.forename: Leslie C
authors.initials: LC
authors.lastname: Pryor
authors.affiliation: Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Dechow
mesh_terms: D000818:Animals; D005075:Biological Evolution; D015519:Bone Density / Q000502:physiology; D000071538:Cortical Bone / Q000502:physiology*; D055119:Elastic Modulus; D005147:Facial Bones / Q000502:physiology*; D002679:Pan troglodytes; D012886:Skull / Q000502:physiology*; D015050:Zygoma / Q000502:physiology
keywords: chimpanzee; cortical bone; elastic moduli; hominid evolution; human