Sex determination by three-dimensional geometric morphometrics of the palate and cranial base

Abstract

The purpose of this study is to assess sexual dimorphism in the palate and base of adult crania using three-dimensional geometric morphometric methods. The study sample consisted of 176 crania of known sex (94 males, 82 females) belonging to individuals who lived during the 20th century in Greece. The three-dimensional co-ordinates of 30 ectocranial landmarks were digitized using a MicroScribe 3DX contact digitizer. Generalized Procrustes Analysis (GPA) was used to obtain size and shape variables for statistical analysis. Three discriminant function analyses were carried out: (1) using PC scores from Procrustes shape space, (2) centroid size alone, and (3) PC scores of GPA residuals which includes InCS for analysis in Procrustes form space. Results indicate that there are shape differences between sexes. In males, the palate is deepest and more elongated; the cranial base is shortened. Sex-specific shape differences for the cross-validated data give better classification results in the cranial base (77.2%) compared with the palate (68.9%). Size alone yielded better results for cranial base (82%) in opposition to palate (63.1%). As anticipated, the classification accuracy improves when both size and shape are combined (90.4% for cranial base, and 74.8% for palate).

Sex determination based on the analysis of a contemporary Polish population’s palatine bones: a computed tomography study of 1,200 patients

“…Taking into account the general morphometric features, male palates analysed in this study were longer, broader and deeper than the female ones, which generally complies with the findings of other authors [5]. However there are works showing that it is the female palate that is actually wider and longer [3].…”

“…Though much has been written on traditional and novel (geometric morphometrics) approaches to sexing human bones, the palatine bones themselves received little attention [3,5,8]. Recent years have brought about an increase of interest in palatal measurements in forensic medicine, mainly due to the introduction of geometric morphometrics [3,8].…”

A quantitative approach for sex estimation based on cranial morphology

“…The centroid size was included as a DV because many earlier studies have found it to differ significantly between males and females (Chovalopoulou et al, ; Franklin et al, ; Nikita, ). Centroid size is computed as the total Euclidean distance of the coordinates of the bregma, nasion, opisthocranion, and superior‐most point on external auditory meatus from their centroid (Figure ).…”

“…A number of studies have adopted metric approaches for estimation of sex using the cranium (e.g., Brasili, Toselli, & Facchini, ; Caple & Stephan, ; Kranioti, İşcan, & Michalodimitrakis, ), while more generalized use of geometric morphometric techniques has facilitated studies that focus on capturing the overall morphology of the cranium or of specific cranial structures (e.g., Bigoni, Velemínská, & Brůžek, ; Chovalopoulou et al, ; Nikita, ). Among those focusing on the morphology of specific cranial structures using geometric morphometry, Garvin and Ruff () explored sexual dimorphism in the supraorbital ridges and mental eminence of US males and females.…”

Study of sexual dimorphism of Malaysian crania: an important step in identification of the skeletal remains

“…A study was done in 176 adult Greek crania, in which the classification accuracy was 82% and 79% for size and shape, respectively, and on cross validation, the classification accuracy was 77.2% [20]. The classification accuracy can be improved when both size and shape were used in combination (90.4% for cranial base), as shown in a study on 106 South African White crania and 90 South African Black crania, in which 13 standard cranial parameters were measured, and the results showed that the classification had yielded from 86.7% up to 97.8% for males, and yielded from 81.1% to 95.8% for females [21].…”