Visitors   Views   Downloads
NOT PEER-REVIEWED
"PeerJ Preprints" is a venue for early communication or feedback before peer review. Data may be preliminary.

A peer-reviewed article of this Preprint also exists.

View peer-reviewed version

Supplemental Information

Cortical bone mechanical properties collected from two cadaveric human specimens

E3 and v23 refer to the elastic (Young’s) modulus and Poisson’s ratio in the axis of maximum stiffness, respectively. For modulus, factor and temperature data were used to distribute regionally variation mechanical properties throughout each of the ALL-HUM models (see Main Text).

DOI: 10.7287/peerj.preprints.2113v1/supp-2

Strain and strain energy density results from simulated premolar bites

Maximum principal strain (MaxPrin), minimum principal strain (MinPrin), strain mode (Mode), maximum shear strain (Shear), von Mises strain, and strain energy density (SED) generated during simulated premolar (P3) biting in the ALL-HUM variants of “extreme” and “average” modern human cranial FEMs. Site numbers follow Fig. 4.

DOI: 10.7287/peerj.preprints.2113v1/supp-3

Strain and strain energy density results from simulated molar bites

Maximum principal strain (MaxPrin), minimum principal strain (MinPrin), strain mode (Mode), maximum shear strain (Shear), von Mises strain, and strain energy density (SED) generated during simulated molar (M2) biting in the ALL-HUM variants of “extreme” and “average” modern human cranial FEMs. Site numbers follow Fig. 4.

DOI: 10.7287/peerj.preprints.2113v1/supp-4

Beam forces used in sensitivity analysis

Total muscle forces, beam count, and force per beam for each muscle group assigned to the GRGL model in the sensitivity analysis. Forces are in Newtons (N).

DOI: 10.7287/peerj.preprints.2113v1/supp-5

In vitro loading of human cranium

Illustration of the loading apparatus constructed for the current analysis within the INSTRON loading machine during loading of the left P3.

DOI: 10.7287/peerj.preprints.2113v1/supp-6

Transparent view of the model under in vitro validation

The surface model is shown in the position it was constrained during muscle loading, as in Fig. S1.

DOI: 10.7287/peerj.preprints.2113v1/supp-7

Principal strain orientations recorded during validation analysis: Sites 1, 2, and 3

Purple lines represent the orientation of minimum principal strain (compression), which is 90° to orientation of maximum principal strain. Black circles represent location of strain gages at the dorsal interorbital (site 1), working-side dorsal orbital (site 2), and balancing-side dorsal orbital (site 3) during in vitro bone strain analysis. Three lines through each gage correspond to the orientation of principal strains during the in vitro loading analysis which were recorded in degrees relative to the A element of the gage.

DOI: 10.7287/peerj.preprints.2113v1/supp-8

Principal strain orientations recorded during validation analysis: Sites 8, 10, and 12 strain

Blue lines represent the orientation of maximum principal strain (tension). Purple lines represent the orientation of minimum principal strain (compression), which is 90° to orientation of maximum principal strain. Black circles represent location of strain gages at the working-side zygomatic root (site 8), working-side infraorbital (site 10), and working-side nasal margin (site 12) during in vitro bone strain analysis. Three lines through each gage correspond to the orientation of principal strains during the in vitro loading analysis which were recorded in degrees relative to the A element of the gage.

DOI: 10.7287/peerj.preprints.2113v1/supp-9

Principal strain orientations recorded during validation analysis: Sites 9 and 11

Blue lines represent the orientation of maximum principal strain (tension). Purple lines represent the orientation of minimum principal strain (compression), which is 90° to orientation of maximum principal strain. Black circles represent location of strain gages at the balancing-side zygomatic root (site 9) and balancing-side infraorbital (site 11) during in vitro bone strain analysis. Three lines through each gage correspond to the orientation of principal strains during the in vitro loading analysis which were recorded in degrees relative to the A element of the gage.

DOI: 10.7287/peerj.preprints.2113v1/supp-10

Principal strain orientations recorded during validation analysis: Sites 4, 6, and 13

Blue lines represent the orientation of maximum principal strain (tension). Purple lines represent the orientation of minimum principal strain (compression), which is 90° to orientation of maximum principal strain. Black circles represent location of strain gages at the working-side postorbital bar (site 4), working-side zygomatic arch (site 6), and the working-side zygomatic body (site 13) during in vitro bone strain analysis. Three lines through each gage correspond to the orientation of principal strains during the in vitro loading analysis which were recorded in degrees relative to the A element of the gage.

DOI: 10.7287/peerj.preprints.2113v1/supp-11

Principal strain orientations recorded during validation analysis: Sites 5, 7, and 14

Blue lines represent the orientation of maximum principal strain (tension). Purple lines represent the orientation of minimum principal strain (compression), which is 90° to orientation of maximum principal strain. Black circles represent location of strain gages at the balancing-side postorbital bar (site 5), balancing-side zygomatic arch (site 7), and balancing-side zygomatic body (site 14) during in vitro bone strain analysis. Three lines through each gage correspond to the orientation of principal strains during the in vitro loading analysis which were recorded in degrees relative to the A element of the gage.

DOI: 10.7287/peerj.preprints.2113v1/supp-12

The GRGL finite element model showing constraints and muscle loads applied following Wroe et al. (2010)

We compared two variants of this “beamed” model to our original “boneloaded” model, one that only included muscle beams for the anterior temporalis, superficial masseter, deep masseter, and medial pterygoid muscles (A), and a second that also included that posterior temporalis (B).

DOI: 10.7287/peerj.preprints.2113v1/supp-13

Results of sensitivity analysis: color maps of von Mises strain magnitudes

Panels show strain distributions during premolar (P3) biting in the (A) original “boneloaded” ALL-HUM model, (B) “beamed” model lacking a posterior temporalis, and (C) “beamed” model including a posterior temporalis. Scales are set to range from 0 – 300 με White regions exceed scale.

DOI: 10.7287/peerj.preprints.2113v1/supp-14

Results of sensitivity analysis: line plot of von Mises strain

Plot shows the microstrain generated during simulated premolar (P3) biting, recorded from 14 identical brick elements across the craniofacial skeletons of our original “boneloaded” model, a “beamed” variant with muscle forces and constraints modeled following Wroe et al. (2010), and a third model analyzed following Wroe et al. (2010) but with the addition of the posterior temporalis (PT) muscle.

DOI: 10.7287/peerj.preprints.2113v1/supp-15

Additional Information

Competing Interests

The authors declare that they have no competing interests.

Author Contributions

Justin A. Ledogar conceived and designed the experiments, performed the experiments, analyzed the data, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.

Paul C. Dechow conceived and designed the experiments, wrote the paper, reviewed drafts of the paper.

Qian Wang conceived and designed the experiments, wrote the paper, reviewed drafts of the paper.

Poorva H Gharpure wrote the paper, reviewed drafts of the paper.

Adam D. Gordon wrote the paper, reviewed drafts of the paper.

Karen L. Baab wrote the paper, reviewed drafts of the paper.

Amanda L. Smith wrote the paper, reviewed drafts of the paper.

Gerhard W. Weber conceived and designed the experiments, wrote the paper, reviewed drafts of the paper.

Ian R. Grosse conceived and designed the experiments, wrote the paper, reviewed drafts of the paper.

Callum F. Ross conceived and designed the experiments, wrote the paper, reviewed drafts of the paper.

Brian G. Richmond conceived and designed the experiments, wrote the paper, reviewed drafts of the paper.

Barth W. Wright conceived and designed the experiments, wrote the paper, reviewed drafts of the paper.

Craig Byron wrote the paper, reviewed drafts of the paper.

Stephen Wroe wrote the paper, reviewed drafts of the paper.

David S. Strait conceived and designed the experiments, wrote the paper, reviewed drafts of the paper.

Data Deposition

The following information was supplied regarding data availability:

Raw data on strain from finite element models and bone mechanical properties are provided in the Supplementary Materials.

Funding

This research was funded by grants from the National Science Foundation Physical Anthropology HOMINID program (NSF BCS 0725219, 0725183, 0725147, 0725141, 0725136, 0725126, 0725122, 0725078), the ‘Biomesh’ grant (NSF DBI 0743460), the EU FP6 Marie Curie Actions MRTN-CT-2005-019564 “EVAN,” a SUNY Albany Dissertation Research Fellowship, and a SUNY Albany GSEU Professional Development Grant. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.


Add your feedback

Before adding feedback, consider if it can be asked as a question instead, and if so then use the Question tab. Pointing out typos is fine, but authors are encouraged to accept only substantially helpful feedback.

Some Markdown syntax is allowed: _italic_ **bold** ^superscript^ ~subscript~ %%blockquote%% [link text](link URL)
 
By posting this you agree to PeerJ's commenting policies