학술논문

The craniomandibular mechanics of being human.
Document Type
Article
Author
Source
Proceedings of the Royal Society B: Biological Sciences. Dec2010, Vol. 277 Issue 1700, p3579-3586. 8p.
Subject
*MASTICATORY muscles
*HUMAN beings
*SKULL
*BIOLOGICAL evolution
*FOOD habits
*MANDIBLE
*TEETH
Language
ISSN
0962-8452
Abstract
Diminished bite force has been considered a defining feature of modern Homo sapiens, an interpretation inferred from the application of two-dimensional lever mechanics and the relative gracility of the human masticatory musculature and skull. This conclusion has various implications with regard to the evolution of human feeding behaviour. However, human dental anatomy suggests a capacity to withstand high loads and two-dimensional lever models greatly simplify muscle architecture, yielding less accurate results than three-dimensional modelling using multiple lines of action. Here, to our knowledge, in the most comprehensive three-dimensional finite element analysis performed to date for any taxon, we ask whether the traditional view that the bite of H. sapiens is weak and the skull too gracile to sustain high bite forces is supported. We further introduce a new method for reconstructing incomplete fossil material. Our findings show that the human masticatory apparatus is highly efficient, capable of producing a relatively powerful bite using low muscle forces. Thus, relative to other members of the superfamily Hominoidea, humans can achieve relatively high bite forces, while overall stresses are reduced. Our findings resolve apparently discordant lines of evidence, i.e. the presence of teeth well adapted to sustain high loads within a lightweight cranium and mandible. [ABSTRACT FROM AUTHOR]