Incisor microwear textures of five bioarcheological groups

Abstract

Dental microwear texture analysis has proven to be a valuable tool for inferring aspects of subsistence behaviour in human groups and diet in other mammals. Studies have to date been limited to molar teeth. Here we report on the first microwear texture analysis of incisors. Five bioarcheological groups were included in this analysis: Aleuts from various islands in the Bering Sea (n ¼ 24), Arikara from the Mobridge site in South Dakota (n ¼ 18), ethnic Chinese cannery workers from Kodiak Island (n ¼ 16), a Late Woodland Bluff sample from Jersey County, Illinois (n ¼ 18) and Puye Pueblo from Pajarito Plateau in New Mexico (n ¼ 18). First, point clouds with 0.18 mm lateral spacing and 0.005 mm vertical resolution were obtained from maxillary central incisor labial surfaces using a white-light confocal profiler. Four adjoining fields were sampled for a total area of 276 mm  204 mm for each specimen. Surface data were then imported into scale-sensitive fractal analysis software for texture characterisation.Results indicate significant variation among groups in anisotropy, fill volume and heterogeneity. These differences are likely related to differences in diet, degrees and types of nondietary incisor use, as well as exposure to abrasives. This study also suggests that texture variables most useful for characterising and comparing incisor microwear may differ from those most useful for distinguishing molar microwear patterns.

Anterior dental microwear texture analysis of the Krapina Neandertals

“…The baseline data were originally published in Krueger and Ungar [34] and Krueger [39] [see also [40]]. Samples include I 1 s of: Aleut (n=24), Arikara (n =18), Illinois Bluff (n =20), Puye Pueblo (n =18), Nunavut Territory (n =27), and Coast Tsimshian (n =25).…”

“…Dental microwear texture analyses of incisor teeth have been especially valuable for distinguishing bioarchaeological/ethnographic groups based on their food preferences, dietary and/or environmental abrasive loads, and non-dietary anterior tooth use practices [34,39]. For example, groups that employ non-dietary anterior tooth use behaviors have lower anisotropy values than those that do not.…”

“…Further, high textural fill volume signaled high-magnitude loading among those groups that utilized non-dietary practices, and especially abrasive diets in those that did not. The latter groups also tended to have more heterogeneous wear surfaces [34,39]. Finally, groups that use their front teeth as tools and have abrasive diets tend to have highly complex microwear textures, those with variation in surface roughness dependent on the scale of observation [39], [see below].…”

“…These individuals have been dated to between 3400 to 400 BP [47]. The average Paleo-Aleut and Neo-Aleut δ 14 C and δ 15 N values are -12.3 and 19.5 and -12.7 and 20.3, respectively [47], suggesting a marine diet of raw and dried fish, sea mammals, and shellfish, supplemented by foxes, rodents, birds, and tubers [34,[46][47][48][49].…”

“…Ethnographic and historic reports suggest the Aleut engaged in non-dietary anterior tooth use behaviors [48,50] including softening wood for boat frames, grasping hides during clothing preparation, and even chewing leather straps for nourishment during lean months [34,[46][47][48][49].…”