Morphological variations in the structure of the jugular foramen of the human skulls of south India

The jugular foramen varies in shape and size from side to side in the same cranium, and in different crania, racial groups and sexes. The foramen's irregular shape, its formation by two bones and the numerous nerves and venous channels that pass through it further compound its anatomy. The shape and size of the foramen is related to the size of sigmoid sinus and the presence or absence of prominent jugular fossa. The present study was undertaken in 125(250 sides) adult south Indian skulls from Department of Anatomy JJM Medical College Davangere Karnataka India. Out of 125 skulls in 64.8% of cases the right foramina were larger than the left, in 24.8% of cases the left foramina were larger than the right and in 10.4% cases were equal on both sides. The jugular fossa present bilaterally in 49.6%, on the right only in 27.2% cases, on the left only in 8.8% cases and was absent in 14.4% cases.