title: Review of In Vivo Bone Strain Studies and Finite Element Models of the Zygomatic Complex in Humans and Nonhuman Primates: Implications for Clinical Research and Practice.
abstract: The craniofacial skeleton is often described in the clinical literature as being comprised of vertical bony pillars, which transmit forces from the toothrow to the neurocranium as axial compressive stresses, reinforced transversely by buttresses. Here, we review the literature on bony microarchitecture, in vivo bone strain, and finite-element modeling of the facial skeleton of humans and nonhuman primates to address questions regarding the structural and functional existence of facial pillars and buttresses. Available bone material properties data do not support the existence of pillars and buttresses in humans or Sapajus apella. Deformation regimes in the zygomatic complex emphasize bending and shear, therefore conceptualizing the zygomatic complex of humans or nonhuman primates as a pillar obscures its patterns of stress, strain, and deformation. Human fossil relatives and chimpanzees exhibit strain regimes corroborating the existence of a canine-frontal pillar, but the notion of a zygomatic pillar has no support. The emerging consensus on patterns of strain and deformation in finite element models (FEMs) of the human facial skeleton corroborates hypotheses in the clinical literature regarding zygomatic complex function, and provide new insights into patterns of failure of titanium and resorbable plates in experimental studies. It is suggested that the "pillar and buttress" model of human craniofacial skeleton function be replaced with FEMs that more accurately and precisely represent in vivo function, and which can serve as the basis for future research into implants used in restoration of occlusal function and fracture repair. Anat Rec, 299:1753-1778, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Morphology, Anatomy Area, Piracicaba Dental School, University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
authors.forename: Felippe Bevilacqua
authors.initials: FB
authors.lastname: Prado
authors.affiliation: Department of Morphology, Anatomy Area, Piracicaba Dental School, University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
authors.forename: Alexandre Rodrigues
authors.initials: AR
authors.lastname: Freire
authors.affiliation: Department of Morphology, Anatomy Area, Piracicaba Dental School, University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
authors.forename: Ana
authors.initials: A
authors.lastname: Cláudia Rossi
authors.affiliation: Zoology Division, School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Ledogar
authors.affiliation: Department of Anthropology, Washington University in St. Louis, Missouri.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Smith
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
authors.affiliation: Zoology Division, School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia.
authors.forename: David S
authors.initials: DS
authors.lastname: Strait
authors.affiliation: Department of Organismal Biology & Anatomy, University of Chicago, Chicago, Illinois.
authors.forename: Tilman
authors.initials: T
authors.lastname: Voigt
authors.affiliation: Department of Organismal Biology & Anatomy, University of Chicago, Chicago, Illinois.
authors.forename: Callum F
authors.initials: CF
authors.lastname: Ross
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D001732:Bite Force; D020342:Finite Element Analysis; D006801:Humans; D008409:Mastication / Q000502:physiology*; D008437:Maxilla / Q000502:physiology*; D011323:Primates; D012886:Skull / Q000502:physiology; D013314:Stress, Mechanical; D015050:Zygoma / Q000502:physiology*
keywords: buttresses; dental implants; pillars; zygomatic fractures; zygomaticomaxillary complex