Does the model reflect the system? When two-dimensional biomechanics is not 'good enough'

Amanda L. Smith, Julian Davis, Olga Panagiotopoulou, Andrea B. Taylor, Chris Robinson, Carol V. Ward, William H. Kimbel, Zeresenay Alemseged, Callum F. Ross

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Models are mathematical representations of systems, processes or phenomena. In biomechanics, finite-element modelling (FEM) can be a powerful tool, allowing biologists to test form-function relationships in silico, replacing or extending results of in vivo experimentation. Although modelling simplifications and assumptions are necessary, as a minimum modelling requirement the results of the simplified model must reflect the biomechanics of the modelled system. In cases where the three-dimensional mechanics of a structure are important determinants of its performance, simplified two-dimensional modelling approaches are likely to produce inaccurate results. The vertebrate mandible is one among many three-dimensional anatomical structures routinely modelled using two-dimensional FE analysis. We thus compare the stress regimes of our published three-dimensional model of the chimpanzee mandible with a published two-dimensional model of the chimpanzee mandible and identify several fundamental differences. We then present a series of two-dimensional and three-dimensional FE modelling experiments that demonstrate how three key modelling parameters, (i) dimensionality, (ii) symmetric geometry, and (iii) constraints, affect deformation and strain regimes of the models. Our results confirm that, in the case of the primate mandible (at least), two-dimensional FEM fails to meet this minimum modelling requirement and should not be used to draw functional, ecological or evolutionary conclusions.

Original languageEnglish (US)
Article number20220536
JournalJournal of the Royal Society Interface
Issue number198
StatePublished - Jan 25 2023


  • biomechanics
  • feeding
  • mandible
  • modelling
  • strain
  • two-dimensional FEA

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Bioengineering
  • Biomaterials
  • Biochemistry
  • Biomedical Engineering


Dive into the research topics of 'Does the model reflect the system? When two-dimensional biomechanics is not 'good enough''. Together they form a unique fingerprint.

Cite this