Morphometric Study of Jugular Foramen and Jugular Fossa of Dried Adult Human Skulls and Its Clinical Significance

Abstract

Abstract Introduction Jugular foramen is one of the most fascinating foramina of the human skull. It is a complex, irregular bony canal located between the occipital bone and petrous part of the temporal bone. Many important structures, like 9th, 10th, 11th cranial nerves, meningeal branch of occipital and ascending pharyngeal arteries, internal jugular vein, and inferior petrosal sinus, are passing through it. The jugular fossa has a septum and a dome. The septum divides the foramen into two compartments: anteromedial compartment (pars nervosa) and posterolateral compartment (pars vascularis). The dome contains superior bulb of internal jugular vein. The architecture of the foramen varies in size, shape, and laterality besides differences related to sex and race. The morphometric measurements of jugular foramen are very important for neurosurgeries and head and neck surgeries. Objectives The aim of the present study is to study the morphology of jugular foramen along with its dimensions, compartments, presence of partial or complete septa and dome. Materials and Methods A total number of 60 jugular foramina were examined from 30 adult dry human skulls of unknown age and sex from the Department of Anatomy, PSG Institute of Medical Sciences and Research, Coimbatore. Measurements were taken using Digital Vernier calipers. Results were analyzed statistically. Results The length, width, and surface area of jugular foramen of right side were measured and compared with the left side. Length and width of the jugular foramen was significantly higher on the right side. The presence of partial septum was found in 27 skulls (90%) on the right side and 29 skulls (99.7%) on the left side, respectively. Dome was present in 100% of the jugular foramina on the right side and 90% of the jugular foramina on the left side. Separate opening for inferior petrosal sinus was found in eight skulls (27%) on the right side and four skulls (13%) on the left side. Conclusion This study provides a clear understanding of anatomy of jugular foramen and supports the reported morphometric variations. The morphometric variations of jugular foramen in the parameters of the skull are probably due to ethnic and racial factors. Knowledge of these variations is important for neurosurgeons and radiologists who deal with space occupying lesions of the structures surrounding jugular foramen. This study may be helpful for ENT surgeons while performing middle ear surgeries.