Ungar P S, Fennell K J, Gordon K, Trinkaus E
Department of Anthropology, University of Arkansas, Fayetteville 72701, USA.
J Hum Evol. 1997 May;32(5):407-21. doi: 10.1006/jhev.1996.0109.
In discussions of the Neandertals, there has been repeated emphasis on the accelerated rate of attrition and the frequent presence of labial beveling of their incisors. Interpretations of this dental attrition have related it to paramasticatory and dietary uses of their anterior teeth as well as to aspects of their facial morphology. In light of this, we examined the rate of beveling (the angle between the labial and incisal surfaces) of central incisors relative to tooth wear in samples of Neandertals, Inuits and Puebloan Amerindians. I1s show little change in the beveling angle with wear and no significant differences between the samples. I1s, however, exhibit a consistent pattern of increased beveling with dental attrition, progressing rapidly until the crown height approximates its labiolinguinal cervical diameter, and then proceeding at a slower rate. All three samples exhibit a similar pattern. However, the Neandertals have significantly greater beveling in more worn teeth than either recent human sample, and the Inuits have nonsignificantly increased beveling relative to the Puebloans in these more worn I1s. In this, it is the degree of development of beveling, not the pattern of beveling, which differentiates the Neandertals. It is hypothesized that the differences between the Neandertals and recent samples could be the product of: (1) contrast in initial incisor procumbency, (2) a labial separation of the maxillary and mandibular incisal occlusal surfaces during edge-to-edge bite, and/or (3) a greater degree of interproximal wear promoting increased "posterior tipping" of the maxillary incisors. The last appears most likely.
