CRANIOSCOPIC, CRANIOMETRIC AND TOPOGRAPHO-ANATOMICAL CHARACTERISTICS OF FORAMEN MAGNUM
Morphoscopic and morphometric analysis of foramen magnum has been provided with 30 skull preparations. The analysis includes determination of foramen magnum collocation with hypoglossal canal and jugular foramen; its longitudinal (M1) and transverse (M8) diameters, length (M7) and width (M16) measurements; cephalic and foramen magnum indexes; foramen magnum, hypoglossal canal and jugular foramen size correlation. The analysis has been provided in 3 groups depending on cephalic index amount, which included brachycrans (21), mesocrans (7) and dolichocrans (2). 5 different shapes of foramen magnum have been recognized. The most common shape in all 3 groups is elliptic, less common are thyroid and rounded shapes, and the rarest shapes are rhomboid and piriform. Hypoglossal canal topography has been researched and it has been detected that distance from its inlet to foramen magnum of occipital bone varies from 3,1 mm to 14,3 mm. In most common cases the distance on the right side is bigger than on the left side. Asymmetry has also been detected in jugular foramen lying towards foramen magnum. Here the left distance is usually bigger. Actual distance varies from 6,2 mm to 21,5 mm.