Functional Morphology of the Mandibular Symphysis of Hominoids Using the Finite Element Method
Year: 2006
Type: article
Abstract: The present study conducted structural analyses of hominoid mandibles by using the finite element method (FEIVD in order to clarlfy functionai adaptations for mastication in primate mandibular symphyses.Three-dimensional finite element models of the mandible of chimpanzee, goriIla and human were constructed, and using these models the stress distributions were compared among three species under the Ioading on the molar and incisor regions.Major findings are as follows.1) Under vertical loading to the molar, high equivalent stress was observed at the lower border of the symphysis in all three species, although the magnitude of the symphyseal stresses under this kind of loading was low compared to that in the entire mandibie.2) Under horizontal loading to the molar, very high equivalent stress was observed on the Iingual side of the symphysis in all three species.3) Under Ioading to the incisor, very high equivalent stress was observed around the loading point and the circumference regardless of the loading orientation and the taxon because there was a load point inside the symphysis.Result 2) confirms Hylander's hypothesis that superior transverse torus (partially inferior transverse torus) was an adaptation to a horizontal external force (bite force and/or muscle force).Moreover, mentum osseum of modern human might function to resist the horizontal load on the molar, since the second peak of equivalent stresses was observed around the area corresponding to mentum osseum.
Author: Masaki Yamashita
Language: English
Topic: Primate Behavior and Ecology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W3102421552