Frontal sinus

The frontal sinus (Latin: sinus frontalis) is a paired air-filled and triangular-shaped cavity located within the frontal bone of the skull. It is the most superior located sinus of all paranasal sinuses.

The frontal sinuses are situated posterior to the superciliary arches of the frontal bone above the glabella. In the posterior direction, they can extend to the lesser wings of the sphenoid bone. Each frontal sinus opens into the middle nasal meatus via the nasofrontal duct.

Blood supply of frontal sinus

The arterial blood vessels supplying the frontal sinus include the supraorbital and anterior ethmoidal arteries. Both arteries are branches of the ophthalmic artery. The venous blood is collected from the sinus by the same-named veins accompanying the arteries. Both veins drain into the superior ophthalmic vein.

Nerve supply of frontal sinus

The sensory innervation of the mucosa is provided by branches of the supraorbital nerve - a terminal branch of the frontal nerve arising from the ophthalmic division (CN V1) of the trigeminal nerve (CN V). Besides the supraorbital nerve, the frontal sinus is also supplied by the orbital branches arising from the pterygopalatine ganglion.