Olfactory fossa depth: CT analysis of 1200 patients.

Background: Olfactory fossa (OF) is a depression in anterior cranial cavity whose floor is formed by cribriform plate of ethmoid. Lateral lamella, which forms its lateral boundary, is a thin plate of bone and is at risk of injury during functional endoscopic sinus surgery, especially when fossa is deep/asymmetric.

Aims: To measure the variations in the depth of OF and categorize Kerala population as per Keros classification using computed tomography (CT).