where is the sinus cavity location
Frontal- one sinus per side, located within the bone of the forehead above the level of the eyes and nasal bridge (figures 1 and 3). Sphenoid- one sinus per side, located behind the ethmoid sinuses; the sphenoid is not seen in a head-on view but is better appreciated looking at a side view (figure 3). The pink membranes lining the sinuses make mucus that is cleared out of the sinus cavities and drains into the nasal passage.