Forensic Sex Estimation of Skeletal Remains Using Frontal Bone Inclination

Sex estimation is one of the first steps in the forensic identification of human skeletal remains, so it is necessary to develop reliable methods for sex estimation for the Croatian population, taking into consideration the population specificity discussed in previous papers. Until now, apart from a small number of studies, sexual dimorphism has not been investigated for the Croatian population (except for the femur, tibia, sternum, and orbits). Therefore, the aim of this study was to analyze the sex dimorphism of the frontal bone inclination in the modern Croatian population using computed tomography (MSCT) scans. The measurement of the inclination of the frontal bone was chosen because it is also important in the morphological sex assessment, but it has not been quantified until now. In total, 180 MSCT images were included in the research; that is, 180 skulls (90 men and 90 women) of known sex and age were analyzed. The frontal (glabellar) angle - the angle enclosed by the line that passes through the glabella parallel to the Frankfurt horizontal plane and tangent to the outline of the frontal bone- was measured. Sexual dimorphism was tested, with the level of statistical significance set at P < 0.05. Discriminant functional analysis was used to obtain a model for sex classification. The measurement of the inclination of the frontal bone showed a statistically significant sexual dimorphism (P < 0.001). The accuracy of sex estimation for men and women and the total sample was 91.3%. This research has shown that the sexual dimorphism of the frontal bone inclination in the modern Croatian population is extremely pronounced and that it can be used in forensic cases to estimate sex. The research also pointed to the importance of using medical images in forensics and the inclusion of non-standard measures in developing standards for sex estimation.