An Anatomical Study of the Jugular Foramen and Its Variations in Dried Adult Human Skulls in Sri Lanka

Abstract

The jugular foramen has a wide ethnic variation in the anatomy and is a well known area for pathological lesions such as glomus tumours, Schwannomas etc, where such lesions are approached by drilling the bone around the jugular foramen. The authors intended to describe the morphometry and anatomical variations of the jugular foramen and the possible dimensional distinction between the jugular foramen and the jugular fossa. A descriptive study of 24 skulls was done regardless of the gender, to describe the mophometry of jugular foramen and jugular fossa along with scaled photographs. Comparisons between the right & left jugular foramen/ jugular fossa and comparison of jugular foramen & jugular fossa on the same side were done using the student t-test. We found that the jugular foramen was present bilaterally in all the skulls studied. The mean ML diameter of the jugular foramen was larger in the right 16.02(±2.46) mm than in the left 15.46(±2.68) mm, which is compatible with previous studies; the mean AP diameters of jugular foramen were 8.28(±1.70) mm on left side and 6.84(±1.76) mm on right side. Therefore the jugular foramen is mophometrically different from jugular fossa at least from the AP diameter (t<0.05 bilaterally) and should be considered as two distinct anatomical structures rather than fossa as a section of foramen. The rest of the variations are possibly due to constitutional, racial, gender related or genetic factors and supports previous established data on Jugular foramen.