Roof of nasal cavity

The roof of the nasal cavity is a narrow, arched structure formed by the contributions of several bones. It can be divided into three segments from anterior to posterior:

• Frontonasal segment (anterior): Formed by the nasal bones and the nasal spine of the frontal bone. This portion slopes downward and forward toward the tip of the nose.

• Cribriform segment (middle): Formed by the cribriform plate of the ethmoid bone, which is the principal component of the roof. This thin, perforated bony plate allows passage of the olfactory nerve filaments (CN I) from the nasal mucosa to the olfactory bulb above. This is the most horizontal and central portion of the roof and is situated at a lower level than the rest, creating a slight depression.

• Sphenoidal segment (posterior): Formed by the body of the sphenoid bone, specifically the anterior face of the sphenoid body and the sphenoidal conchae (or vaginal process). This portion slopes downward and backward toward the nasopharynx. The opening of the sphenoid sinus (sphenoid ostium) is located in this region.