The ethmoidal sinus roof: anatomical relationships with the intracranial cavity.

A detailed understanding of the relationship between the ethmoidal sinus and the intracranial cavity is essential to prevent intracranial penetration during orbital surgery. The authors analyzed 10 postmortem orbits with their adjacent skull bases of 5 Asian cadavers (3 males and 2 females; mean age of 80 years at death). After removing all orbital contents, skull and brain, the medial orbital wall, ethmoidal cells, and ethmoidal roof were also removed. From the intracranial cavity view, the ethmoidal roof was situated just lateral to the cribriform plate. From the orbital view, the location of the roof was close to the superior border of the medial orbital wall. These anatomical observations may be useful to prevent intracranial penetration and cerebrospinal fluid leakage during medial orbital wall decompression.