A Comparative Study of the Anatomy of the Jugular Foramen and Its Variations in Dried Adult Human Skulls in Sri Lankan Population

The jugular foramen known to have a wide variation among different ethnicities for its anatomical variations and is also a well known area for pathological lesions such as glomus tumours, Schwannomas etc. The treatment of such lesions often involves drilling the bony area around the jugular foramen. In this study the main intention of the authors are to describe the morphometry and anatomical variations of the jugular foramen and also explain the possible dimensional distinction between the jugular foramen and the jugular fossa. A descriptive study of 27 skulls was done regardless of the gender, to describe the morphometry of jugular foramen and jugular fossa along with scaled photographs. Comparisons between the right and left jugular foramen /Jugular fossa and comparison of jugular foramen and jugular fossa on the same side were done using the student t-test. The jugular foramen was present bilaterally in all the skulls studied. The mean ML diameter of the jugular foramen was larger in the right 12.62 mm than in the left 12 mm, which is compatible with previous studies; the mean AP diameters of jugular foramen were 7.62 mm on the left side and 6.92mm on the right side. It can be concluded from the above data that the jugular foramen is morphometrically different from the jugular fossa at least from the AP diameter (t<0.05 bilaterally) and should be considered as two distinct anatomical structures rather than the fossa being considered as part of the jugular foramen. The rest of the variations observed are possibly due to constitutional, racial, gender related or genetic factors which are supported by the data from previously performed studies.