Anatom3DFrontal sinus
Sinus frontalis · Čelní dutina
Respiratory system
Looks like
An air-filled space inside the frontal bone above each eyebrow, often unequal on each side.
What it does
Lightens the skull and drains into the nose.
Keeping it well
Sinusitis usually settles in 10 days; swelling of the forehead or eyelid with fever needs urgent care as infection can spread inward.