Sexual dimorphism of foramen magnum between two different groups of Indian population: A cross-sectional cone-beam computed tomography study

The foramen magnum (FM), being a vital landmark at the base of the skull, includes interests to many fields of medicine. Many authors have recounted the usefulness of the FM in gender determination. The emphasis of this study is to evaluate the shape and dimensions of the FM among males and females and to establish its role in sexual dimorphism using cone-beam computed tomography (CBCT). Furthermore, to evaluate the area and FM index (FMI) among males and females and finally to evaluate the differences in FM measurements if any in two different regions of an Indian population. One hundred and ten CBCT scans (55 males and 55 females; age range, 20–80 years) were selected for this study. The sagittal diameter, transverse diameter, area, FMI, and circumference of FM were measured, and data were subjected to discriminant analysis for the evaluation of sexual dimorphism. The area of FM was the best discriminant parameter which was used to study the sexual dimorphism with an overall accuracy of 90.9%. It can be concluded that the reconstructed CBCT image provides valuable measurements for the FM and could be used for gender determination