Morphometric study of jugular foramen in adult South Indian skulls

IntroductionThe jugular foramen lies between the occipital bone and the petrosal portion of the temporal bone. It allows the passage of important nervous and vascular vein and inferior petrosal sinus. Glomic tumors, schwannomas, metastatic lesions and infiltrating inflammatory processes are associated with this foramen, which can account for injuries of related structures. Morphometric study of this foramen will serve as guide for imaging and operative procedures in the jugular foramen region.Material and methodsOne hundred and sixteen dry adult skulls of unknown sex of south Indian origin were utilized for this study. Following dimensions of the foramen were measured with the help of a digital vernier caliper: i) Maximum dimension along the long axis; ii) Maximum dimension perpendicular to the long axis; iii) Maximum height of dome of jugular fossa and iv) Distance of stylomastoid foramen from lateral margin of jugular foramen. The minimum distance of stylomastoid foramen from the lateral margin of the foramen was also measured.ObservationsThe findings of the present study bring forth some important facts as follows: On an average, all the dimensions measured were more on the right side. The jugular fossa showed great variability ranging from total absence of fossa to deep excavation anterolaterally forming a large fossa with the well-defined roof.ConclusionThese observations call for further studies on variability of jugular fossa and its possible implications. The distance of the stylomastoid foramen from the jugular foramen will serve as guide for operating surgeons using infratemporal approach during skull base surgeries.