Enamel thickness of deciduous and permanent molars in modern Homo sapiens
Version of Record online: 7 OCT 2004
Copyright © 2004 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 126, Issue 1, pages 14–31, January 2005
How to Cite
Grine, F.E. (2005), Enamel thickness of deciduous and permanent molars in modern Homo sapiens. Am. J. Phys. Anthropol., 126: 14–31. doi: 10.1002/ajpa.10277
- Issue online: 19 NOV 2004
- Version of Record online: 7 OCT 2004
- Manuscript Accepted: 13 DEC 2002
- Manuscript Received: 19 JUN 2002
- NSF. Grant Number: SBR 9804882
- enamel thickness;
This study presents data on the enamel thickness of deciduous (dm2) and permanent (M1–M3) molars for a geographically diverse sample of modern humans. Measurements were recorded from sections through the mesial cusps of unworn teeth. Enamel is significantly thinner on deciduous than on permanent molars, and there is a distinct trend for enamel to increase in relative thickness from M1 to M3. The relatively thicker enamel of M2s and especially M3s can be related to the overall reduction in size of more distal molar crowns, which has been attained through a differential loss of the dentine component. Enamel tends to be thicker on the protocone than on the paracone, and thicker on the protoconid than on the metaconid, but its distribution is not wholly concordant with models that predict increased thickness as a means by which to counter heavier attritional loss on these “functional” cusps. Indeed, the thickness of enamel tends to be more variable on cusp tips and occlusal surfaces than over the lateral aspects of cusps. The proportionately thicker enamel over the lateral aspects of the protocone and protoconid more likely serves as a means to prolong functional crown life by preventing cusp fracture, rather than being an adaptation to increase the attritional longevity of wear facets. The present data suggest that the human dentition is not predisposed to develop a helicoidal wear plane through the disposition of molar enamel thickness. Am J Phys Anthropol, 2004. © 2004 Wiley-Liss, Inc.