Journal article
The ontogeny of the chin: an analysis of allometric and biomechanical scaling
Journal of anatomy, Vol.226(6), pp.549-559
06/01/2015
DOI: 10.1111/joa.12307
PMCID: PMC4450959
PMID: 25865897
Abstract
The presence of a prominent chin in modern humans has been viewed by some researchers as an architectural adaptation to buttress the anterior corpus from bending stresses during mastication. In contrast, ontogenetic studies of mandibular symphyseal form suggest that a prominent chin results from the complex spatial interaction between the symphysis and surrounding soft tissue and skeletal anatomy during development. While variation in chin prominence is clearly influenced by differential growth and spatial constraints, it is unclear to what degree these developmental dynamics influence the mechanical properties of the symphysis. That is, do ontogenetic changes in symphyseal shape result in increased symphyseal bending resistance? We examined ontogenetic changes in the mechanical properties and shape of the symphysis using subjects from a longitudinal cephalometric growth study with ages ranging from 3 to 20+years. We first examined whether ontogenetic changes in symphyseal shape were correlated with symphyseal vertical bending and wishboning resistance using multivariate regression. Secondly, we examined ontogenetic scaling of bending resistance relative to bending moment arm lengths. An ontogenetic increase in chin prominence was associated with decreased vertical bending resistance, while wishboning resistance was uncorrelated with ontogenetic development of the chin. Relative to bending moment arm lengths, vertical bending resistance scaled with significant negative allometry whereas wishboning resistance scaled isometrically. These results suggest a complex interaction between symphyseal ontogeny and bending resistance, and indicate that ontogenetic increases in chin projection do not provide greater bending resistance to the mandibular symphysis.
Details
- Title: Subtitle
- The ontogeny of the chin: an analysis of allometric and biomechanical scaling
- Creators
- N. E. Holton - University of IowaL. L. Bonner - University of IowaJ. E. Scott - University of IowaS. D. Marshall - University of IowaR. G. Franciscus - University of IowaT. E. Southard - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of anatomy, Vol.226(6), pp.549-559
- DOI
- 10.1111/joa.12307
- PMID
- 25865897
- PMCID
- PMC4450959
- NLM abbreviation
- J Anat
- ISSN
- 0021-8782
- eISSN
- 1469-7580
- Publisher
- Wiley
- Number of pages
- 11
- Language
- English
- Date published
- 06/01/2015
- Academic Unit
- Orthodontics; Anthropology; Anatomy and Cell Biology; Craniofacial Anomalies Research Center
- Record Identifier
- 9984271556402771
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