Supraorbital air cells

Supraorbital air cells are an anatomical variant of the paranasal sinuses. They consist of cells originating from the anterior ethmoid air cells extending posteriorly and superiorly over the orbit from the frontal recess. They may mimic septated frontal sinuses as their posterior wall is the skull base.

Gross anatomy

These cells consist of pneumatization of the orbital plate of the frontal bone posterior to the frontal sinus and frontal recess. They usually drain into the lateral aspect of the frontal recess.

They are identified in approximately 25-35% of subjects and can be multiple in up to 5% of individuals.

Practical points

When a supraorbital cell is present, care should be taken on pre-functional endoscopic sinus surgery imaging studies to identify the anterior ethmoidal notch as the anterior ethmoidal artery is usually seen freely traveling within the ethmoid air cells and thus at greater risk of intraoperative injury. Moreover, these cells may contribute to obstructing the frontal recess and may be mistaken preoperatively for the frontal recess.