Figure 1.
Digital reconstruction of the gorilla specimen ZMB-31626 (lower left second molar – LM2).
The three dental traits examined in this study (protostylid, trigonid crest, entoconid-hypoconulid crest) are highlighted both in the crown (top) and in the enamel-dentine junction (bottom).
Figure 2.
Basic steps to create the volumetric mesh and to recognize the contact areas for specimen ZMB-31435.
A, dental tissues and supporting structures for the lower left second molar (LM2) of specimen ZMB-31435. B, collision detection for specimen ZMB-31435 in the Occlusal Fingerprint Analyser (OFA) software during maximum intercuspation contact situation; the LM1-LM2 are transparent to show the collision (red spots) in the occlusal surface of the LM2 (see also Video S1). C, the FE mesh of specimen ZMB-31435 consisting of 2,482,913 ten-nodded tetrahedral elements. PDL = periodontal ligament; B = buccal; D = distal; L = lingual; M = mesial.
Figure 3.
Loading position and direction for specimen ZMB-31435, ZMB-31626 and ZMB-83551.
For each lower left second molar (LM2) only the volumetric mesh of the enamel is displayed. The load (red arrows) was distributed proportionally according to the occlusal contact areas detected in the Occlusal Fingerprint Analyser (OFA) software (see also Video S1-S3). B = buccak; D = distal; L = lingual; M = mesial.
Figure 4.
The enamel volumetric meshes of specimen ZMB-31435 and ZMB-31435sim.
A, the volumetric mesh of specimen ZMB-31435 LM2 with highlighted the crests considered in the simulation. B, the volumetric mesh with artificial mesiodistal grooves interrupting the trigonid and entoconid-hypoconulid crests (specimen ZMB-31435sim).
Figure 5.
Maximum principal stress distribution observed in ZMB-31435 LM2 (left), ZMB-31626 LM2 (middle) and ZMB-83551 LM2 (right) during maximum intercuspation contact.
Blue areas mark the position were occlusal forces were applied. First row = occlusal view; second row = buccal view; third row = lingual view. B = buccal; D = distal; L = lingual; M = mesial.
Figure 6.
Sections of the enamel volumetric meshes along the buccolingual groove (A-A) and mesiodistal groove (B–B).
A, specimen ZMB-31435 LM2. B, specimen ZMB-31626 LM2. C, specimen ZMB-83551 LM2.
Figure 7.
Maximum principal stress distribution in ZMB-31435 LM2 and ZMB-31435sim LM2 during a representative time-step of phase I.
Blue areas on the occlusal surface mark the position were occlusal forces were applied, and red areas show maximum tensile stress. The plot on the right side shows the differences in tensile stress values between the two specimens based on 14 homologous nodes selected on the occlusal grooves.