Above the eyes, in the forehead bone.
1 Maxillary sinuses: These are the largest of the sinuses and are located behind the cheekbones near the maxillae, or upper jaws. 2  Sphenoid sinuses: The sphenoid sinuses are located in the sphenoid bone near the optic nerve and the pituitary gland on the side of the skull. The paranasal sinuses (“the sinuses”) are air-filled cavities located within the bones of the face and around the nasal cavity and eyes. Each sinus is named for the bone in which it is located: Physiology. The sinus cavities, proper term paranasal sinuses, are hollow air-filled cavities in the skull located around the nasal cavity. These rather unassuming pockets in the skull bone may have several important functions and are also prone to diseases that affect 1 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). 2  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). : frontal sinuses, sitting within the front bone in the forehead Purple: ethmoid sinuses, located between the eyes Coral: sphenoid sinuses, located centrally in the skull just behind the nasal cavity under the front part of the brain Blue: maxillary sinuses, located in the cheek. The sinuses are air filled cavities located in the face and around the nose. The sinuses are named according to the bone in which they are located. There are four paired sinus cavities. The maxillary sinuses are located in each cheek bone. The ethmoid sinuses are located between the eyes. There are four pairs of paranasal sinuses, the frontal sinuses are located above the eyes, in the forehead bone. The maxillary sinuses (antra of Highmore) are located in the cheekbones, under the eyes. The ethmoid sinuses, also called ethmoid labyrinth are located between the eyes and the nose. The maxillary sinuses are the largest of the paranasal sinuses and located in the body of the maxilla (upper jaw). It is the sinus that is the most likely to become infected and given its size and close proximity to other key structures on the skull, there is a risk of the infection spreading.
http://www.healthline.com/human-body-maps/sinus-cavities-sinuses http://care.american-rhinologic.org/sinus_anatomy http://www.healthhype.com/sinus-cavities-paranasal-sinuses-location-anatomy-pictures.html http://care.american-rhinologic.org/sinus_anatomy http://sinusallergy.osu.edu/22631.cfm http://www.ohiosinus.com/patient-info/sinus-anatomy-and-function http://www.ghorayeb.com/AnatomySinuses.html http://www.healthhype.com/sinus-cavities-paranasal-sinuses-location-anatomy-pictures.html
where is sinus located