Quantitative evaluation of the facial morphology of a Tolteca figurine from Mexico using geometric morphometric approaches / Evaluación cuantitativa de la morfología facial de una figura Tolteca de México utilizando la morfometría geométrica

Morphometric approaches can be combined with 2D or 3D imaging to quantitatively evaluate craniofacial medical conditions depicted in material culture and to learn more about the culture being studied. A terra-cotta figurine (circa 500 A.D.) from the Tolteca culture of Mexico has previously been qualitatively "diagnosed" with Down syndrome (DS) based on the presence or absence of facial features typically associated with trisomy 21. The purpose of this research is to quantitatively test the hypothesis that the Tolteca figurine exhibits facial features consistent with DS. Landmarks (n = 24) were acquired from sex- and age-matched (5-20 yrs) facial images of DS individuals (n = 32), euploid individuals (n = 32), and the Tolteca figurine. Landmark coordinates were subjected to geometric morphometric analyses, and the results suggest that the Tolteca figurine displays facial morphology consistent with DS.

Con el objetivo de evaluar cuantitativamente las complejas condiciones medicas craneofaciales, se pueden combinar los enfoques morfométricos con imágenes 2D o 3D representadas en la cultura material, para un mayor conocimiento referente al estudio cultural. Una figura de terracota (alrededor del 500 DC) de la cultura Tolteca de México ha sido previamente y cualitativamente "diagnosticada" con Síndrome de Down en base a la presencia o ausencia de rasgos faciales típicamente asociados con trisomía 21. El propósito de esta investigación fue comprobar cuantitativamente la hipótesis de que esta figura de la cultura Tolteca exhibe rasgos faciales consistentes con Síndrome de Down. Se identificaron puntos de referencia similares (n = 24) según sexo y edad (5-20 años) a imágenes faciales de individuos con Síndrome de Down (n = 32), individuos euploides (n = 32) y de la figura Tolteca. Los puntos de referencia fueron sometidos a un análisis morfométrico geométrico, y los resultados sugieren que la morfología facial de la figura Tolteca es consistente con el Síndrome de Down.

Difference in dental arch form between Angle Ⅱ division 1 and normal occlusion assessed by Euclidean distance matrix analysis / 实用口腔医学杂志

Objective: To evaluate differences in dental arch forms between the subjects with Angle II division 1(AngleⅡ1 ) and those with normal occlusion. Methods:60 AngleⅡ1 patients and 60 normal occlusion subjects aged 13-17 years old were selected. Fourteen landmarks, corresponding to the cusp tips and incisor edges, were identified on the upper and lower dental casts of all subjects by YM-21115 three dimension measuring machine. Arch form differences between AngleⅡ1 and normal occlusion subjects were assessed by Euclidean distance matrix analysis (EDMA). Results:(1) In both sexes, the upper arch of AngleⅡ1 subjects was larger than that of normal occlusion (1.8% for females and 2.7% for males); and arch shape difference was also significantly different(P