"blood supply: supratrochlear, supraorbital and anterior ethmoidal arteries"
"The frontal sinus has two chambers, one on each side, and they are almost always asymmetrical and separated by a septum. Each sinus extends superior to the medial end of the eyebrow and back into the orbital portion of the frontal bone. However, three or more chambers may be present in ~10% (range 1.5%-21%). It is divided by thin bony intrasinus septa, usually off-midline and rarely dehiscent."