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Cited by 67Pleistocene-Era Hominins and ArchaeologyMorphological variations and asymmetryForensic Anthropology and Bioarchaeology Studies

Why do humans have chins? Testing the mechanical significance of modern human symphyseal morphology with finite element analysis

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Gröning, Flora, Liu, Jia, Fagan, Michael J., O'Higgins, Paul·2011·American Journal of Physical Anthropology
DOI 10.1002/ajpa.21447
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Abstract

The modern human mandibular symphysis differs from those of all other primates in being vertically orientated and possessing a chin, but the functional significance of this unique morphology is not well understood. Some hypotheses propose that it is an adaptation to specific loads occurring during masticatory function. This study uses finite element analysis to examine these symphyseal loads in a model of a modern human mandible. By modifying the symphyseal cross‐sectional form, the mechanical significance of the presence of the chin and symphyseal orientation is tested, and modern human and Neanderthal symphyseal cross‐sections are compared with regard to their ability to withstand different loads. The results show that changes in symphyseal form have profound effects on the strains. The presence of a chin leads to lower symphyseal strains overall, whereas a vertical orientation of the symphysis results in higher strains under wishboning, but not under vertical bending in the coronal plane and dorsoventral shear. Compared to Neanderthals, the modern human symphysis shows higher strains during dorsoventral shear and wishboning, but is as effective as the Neanderthal symphysis in resisting vertical bending in the coronal plane and the loads resulting from simulated incision and unilateral molar biting. In general, the results of this study corroborate prior hypotheses about the mechanical effects of the human chin and vertical symphyseal orientation and support the idea that the relative importance of wishboning and vertical bending in the coronal plane might have played a role in the evolution of modern human symphyseal morphology. Am J Phys Anthropol, 2011. © 2010 Wiley‐Liss, Inc.

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  • The large midface, chinless jaws and enlarged brow ridges of Middle Pleistocene hominins make up a suite of features adapted to masticatory or paramasticatory uses.

    “the large midface, chinless jaws and enlarged brow ridges of MP hominins make up a suite of features adapted to masticatory or paramasticatory uses 59,60,65,66”

    From The evolutionary history of the human face (2019) · cites this paper as [65]

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Authors
Gröning, F., Liu, J., Fagan, M. J., & O'Higgins, P.
Affiliations
  • University of York (GB)
  • University of Hull (GB)
Corresponding author
Gröning, Flora
ORCID
Venue
American Journal of Physical Anthropology
Publisher
Wiley
Published
2010-12-16
Volume
144
Issue
4
Pages
593-606
ISSN
  • 0002-9483 (ISSN-L)
  • 1096-8644
DOI
10.1002/ajpa.21447
OpenAlex
W2076724596
Cited by
67
References
65
Citations by year
2026: 7 · 2025: 2 · 2024: 4 · 2022: 5 · 2021: 3 · 2020: 2 · 2019: 4 · 2018: 5 · 2017: 3 · 2016: 4 · 2015: 5 · 2014: 3 · 2013: 10 · 2012: 6
FWCI
27.34
Type
journal article
Language
en
Open access
Licence
Locations
  • American Journal of Physical Anthropology (publishedVersion)
  • PubMed (publishedVersion)
  • Repository@Hull (Worktribe) (University of Hull) (submittedVersion, cc-by)
Funders
Biotechnology and Biological Sciences Research Council (BB/E014259/1, BB/E007813/1, BB/E013805/1, BB/E009204/1)
Topics
  • Social Sciences › Anthropology › Pleistocene-Era Hominins and Archaeology
  • Physical Sciences › Mathematics › Geometry and Topology › Morphological variations and asymmetry
  • Social Sciences › Arts and Humanities › Archeology › Forensic Anthropology and Bioarchaeology Studies
Keywords
mandibular symphysis, chin, mastication, vertical bending, mechanical loading, strain distribution, incision, human evolution
MeSH terms
Animals, Biomechanical Phenomena, Chin, Fossils, Humans, Mastication, Models, Biological, Radiography, Hominidae, Tomography Scanners, X-Ray Computed, Weight-Bearing, Finite Element Analysis

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