Foramen cecum

The foramen cecum represents a primitive tract between the anterior cranial fossa and the nasal space. It is located along the anterior cranial fossa, anterior to the cribriform plate of the ethmoid bone and posterior to the frontal bone, within the frontoethmoidal suture. It lies at a variable distance anterior to the crista galli.

During embryologic development, the foramen cecum contains a dural diverticulum which extends from the anterior cranial fossa to the dermal surface of the nose. Normally, the dural diverticulum undergoes complete involution and the foramen cecum fills in with fibrous tissue and variably ossifies .

Ossification of the anterior cranial fossa and crista galli is usually incomplete at birth and progresses through the first few years of life . Thus, the foramen cecum is frequently found in infants, uncommonly in children, and rarely in adults where <1.5% of foramina remain open. It rarely transmits emissary venous connections (intra- or extracranial) to the nasal cavity.

A variety of midline nasal pathologies may occur along this transient embryologic communication :