Measurements of the Foramen Magnum and Mandible in Relation to Sex UsingCBCT

Abstract

The purpose of this study was to evaluate pre-existing CBCT images of a large sample of adult females and males to provide data on foramen magnum and mandibular measures of sexual dimorphism for use as a reference sample in cases of establishing identity in unknown fragmentary skulls. The study group consisted of 161 adult patients. 3D images of the patients were assessed retrospectively. FM measurements were obtained from reformatted axial sections. Six mandibular measurements were taken. According to the results, the study identified four mandibular measurements as final predictors of sex which are as follows: the gonial angle (G-angle) and ramus length (Ramus-L), gonion-gnathion length (G-G-L) and bigonial breadth (BG-Br). It was found that the cross-validated grouped overall predictive accuracy was 83.2% for FM and mandible measurements. It could correctly identify males in 77.3% and females in 87.4% of the cases. To assess sexual dimorphism, the gonial angle and ramus, gonion-gnathion lengths, and bigonial breadth of the mandible and sagittal diameter of the FM may be used on CBCT images.

Morphometric analysis of the foramen magnum using cone beam computed tomography

“…The means of its transverse diameter were 31.2 mm and 29.8 mm in males and females, respectively. Our results were very similar to those of previous studies (6,20,21,24). In the literature, there is a limited number of studies about the measurement of FM circumference (6,16,24).…”

“…In the present study, the means of FM circumference were recorded as 107.9 mm and 102.7 mm in males and females, respectively, and a statistically significant difference was found between Chi-square = 9.648, P = 0.209 the sexes. These results were very similar to the results reported by Ilgüy et al (24) and each of two studies findings' were overestimated. This condition may be related to either the use of the same imaging method (CBCT) or racial similarities of the study samples in both of them.…”

“…The initial material of study consisted of the demographic data (sex and age) and CBCT images of 400 patients who presented to the Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gazi University, between November 2014 and January 2015. The inclusion and exclusion criteria of the study were determined and modified in accordance with previous studies (6,20,(22)(23)(24). The inclusion criteria were: 1) no trauma and surgery history of the head, 2) CBCT images are good quality and free of artifacts, 3) facescanned CBCT images (field of view: 200 × 170 cm).…”

Assessment of the opening diameter of the incisive foramen as a parameter for gender and age estimation

“…Moreover, because maxillary bones and dental elements are highly mineralised and surrounded by soft tissues, they tend to resist to adverse environmental conditions, thus preserving anatomical accidents and characters for long periods of time [3,4].…”

“…However, this procedure is challenged with situations in which there are a few bone fragments or remnants of pelvis or skull [3,5,6]. In this context, research on forensic dentistry and anthropology have associated the use of image technology to the study of bone anatomy for obtaining clues which can guide the estimation of gender and age in such situations [6][7][8].…”