INVESTIGADORES
BERNAL Valeria
artículos
Título:
Size and Shape Analysis of Human Molars: Comparing Traditional and Geometric Morphometric Techniques
Autor/es:
BERNAL V.
Revista:
HOMO Journal of Comparative Human Biology
Referencias:
Año: 2007 p. 279 - 296
ISSN:
0018-442X
Resumen:
Dental size and shape have been
widely used to study biological relationships among human populations. Although
several techniques have been proposed to quantify dental form, few attempts
have been made to compare results obtained by application of different
techniques. This work aims at comparing the information about size and shape of
molar contours obtained from linear measurements, landmarks and semi-landmarks
as well as evaluating the variation patterns among populations obtained by each
method. The crowns of 35 permanent upper second molars belonging to
archaeological samples from three regions of Argentina were analyzed. Buccolingual and
mesiodistal crown diameters were measured and centroid size and crown index
were used as size and shape descriptors, respectively. Likewise, four landmarks
and 79 semi-landmarks were collected from the molar outline and relative warps (RW)
analysis was performed on partial warps and uniform vectors; centroid size was estimated
to summarize tooth size. The results indicate that size was consistently
estimated by the three variable types. On the contrary, noticeable differences
were found when the results of molar shape described by linear measurements
were compared with those obtained using either landmarks or semi-landmarks.
This study shows that considerable information about molar contour is added by
using landmarks instead of crown diameters and that some morphological
features, such as degree of cusp development, can only be captured by means of
semi-landmark analysis. Finally, the interpretation of similarities among
samples differs according to the selected description system.