Effects of cropping, smoothing, triangle count, and mesh resolution on 6 dental topographic metrics

Berthaume, Michael A.; Winchester, Julia; Kupczik, Kornelius

Abstract

Dental topography is a widely used method for quantifying dental morphology and inferring dietary ecology in animals. Differences in methodology have brought into question the comparability of different studies. Using primate mandibular second molars, we investigated the effects of mesh preparation parameters smoothing, cropping, and triangle count/mesh resolution (herein, resolution) on six topographic variables (Dirichlet normal energy, DNE; orientation patch count rotated, OPCR; relief index, RFI; ambient occlusion, portion de ciel visible, PCV; enamel surface area, SA; tooth size) to determine the effects of smoothing, cropping, and triangle count/resolution on topographic values and the relationship between these values and diet. All topographic metrics are sensitive to smoothing, cropping method, and triangle count/resolution. In general, smoothing decreased DNE, OPCR, RFI, and SA, increased PCV, and had no predictable effect on tooth size. Relative to the basin cut off (BCO) cropping method, the entire enamel cap (EEC) method increased RFI, SA, and size, and had no predictable effect on DNE and OPCR. Smoothing and cropping affected DNE/OPCR and surfaces with low triangle counts more than other metrics and surfaces with high triangle counts. There was a positive correlation between DNE/OPCR and triangle count/resolution, and the rate of increase was weakly correlated to diet. PCV tended to converge or decrease with increases in triangle count/resolution, and RFI, SA, and size converged. Finally, there appears to be no optimal triangle count or resolution for predicting diet from this sample, and constant triangle count appeared to perform better than constant resolution for predicting diet.

Citation

Berthaume, M. A., Winchester, J., & Kupczik, K. (2019). Effects of cropping, smoothing, triangle count, and mesh resolution on 6 dental topographic metrics. PLoS ONE, 14(5), Article e0216229. https://doi.org/10.1371/journal.pone.0216229

• Journal Article Type: Article
• Acceptance Date: Apr 16, 2019
• Online Publication Date: May 6, 2019
• Publication Date: May 31, 2019
• Deposit Date: May 29, 2019
• Publicly Available Date: May 29, 2019
• Journal: PLoS ONE
• Electronic ISSN: 1932-6203
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 5
• Article Number: e0216229
• DOI: https://doi.org/10.1371/journal.pone.0216229
• Public URL: https://durham-repository.worktribe.com/output/1329852