Introduction: The sphenoid sinus is considered to be morphologically one of the most variable structures in the human body. Aim: The aim of this study was to analyse the variants of pneumatisation of sphenoid bone and to determine differences in relation to the gender and body side in the population of Vojvodina. Material and methods: This retrospective study included 60 patients (30 males and 30 females), mean age 39.92 years, who underwent a CT scan of paranasal sinuses in the Center of Radiology, Clinical Center of Vojvodina, Novi Sad. The total number of analysed sinuses was 120. The CT scan images were presented in coronal, sagittal and axial planes. The types and the extensions of sinus were analysed. Results: The most common type of the sphenoid sinus was sellar (83.33%), followed by presellar (15.83%). The conchal type was found in only one case (0.83%). The most frequent subtype of the posterior extension in males was subdorsal (48%) and in females subtype body (42%). The presence of both lateral and anterior extensions was found in 18.33% cases, only lateral extension in 45% cases and only anterior in 10%. Conclusion: The most common type of sphenoid sinus was sellar, while the conchal type was the rarest one. The most frequent subtype was subdorsal in males and subtype body in females. The lateral extension was observed more often in comparison to the anterior extension.

The carotid canal is located in the petrous part of the temporal bone and transmits the internal carotid artery along with the venous and sympathetic nerve plexus. The shape, location and dimensions of the carotid canal are clinically very important especially in cases of skull base surgery. The aim of this study was to investigate the morphological and morphometric parameters of the external aperture of the carotid canal in Serbian population. The study included 24 dry adult skulls and 36 dry adult temporal bones. Diameters and distances of the external aperture of the carotid canal from various important landmarks of the skull base were measured. The shape of the external carotid canal aperture was also noted. Digital data were processed in the ImageJ software. The average length of the external aperture of the carotid canal in all investigated specimens (skulls and temporal bones) on the right and left sides was 7.31±1.01 mm and 7.71±1.06 mm, respectively. The average width of the external aperture of the carotid canal on the right side was 5.82±0.78 mm while on the left side was 6.20±1.04 mm. The frequency of different shapes of the external aperture of the carotid canal was as follows: round in 45 (53.57 %), oval in 25 (29.76 %), and the rarest was almond shape noted in 13 (15.47 %) cases. There were no statistically significant differences in all measured parameters between genders and body sides. The only statistical significance was found in females between right and left side in relation with length (AP diameter) of the external aperture of the carotid canal. The results of this study will be useful for neurosurgeons to improve different surgical approaches to the petrous part of the internal carotid artery and prevent its complications.