Comparison of dental measurement systems for taxonomic assignment of first molars

Stefano Benazzi, Michael Coquerelle, Luca Fiorenza, Fred L Bookstein, Stanislav Katina, Ottmar Kullmer

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38 Citations (Scopus)

Abstract

Morphometrics of the molar crown is based traditionally on diameter measurements but is nowadays more often based on 2D image analysis of crown outlines. An alternative approach involves measurements at the level of the cervical line. We compare the information content of the two options in a three-dimensional (3D) digital sample of lower and upper first molars (M(1) and M(1) ) of modern human and Neanderthal teeth. The cervical outline for each tooth was created by digitizing the cervical line and then sectioning the tooth with a best fit plane. The crown outline was projected onto this same plane. The curves were analyzed by direct extraction of diameters, diagonals, and area and also by principal component analysis either of the residuals obtained by regressing out these measurements from the radii (shape information) or directly by the radii (size and shape information). For M(1) , the crown and cervical outline radii allow us to discriminate between Neanderthals and modern humans with 90 and 95 accuracy, respectively. Fairly good discrimination between the groups (80-82.5 ) was also obtained using cervical measurements. With respect to M(1) , general overlap of the two groups was obtained by both crown and cervical measurements; however, the two taxa were differentiable by crown outline residuals (90-97 ). Accordingly, while crown diameters or crown radii should be used for taxonomic analysis of unworn or slightly worn M(1) s, the crown outline, after regressing out size information, could be promising for taxonomic assignment of lower M1s.
Original languageEnglish
Pages (from-to)342 - 354
Number of pages13
JournalAmerican Journal of Physical Anthropology
Volume144
Issue number3
DOIs
Publication statusPublished - 2010
Externally publishedYes

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