Sinus pain under the cheekbone usually indicates an abnormality of the largest of the nasal sinuses, called the maxillary sinus. That sinus is located directly under the cheekbone and covers the area from just above the upper teeth to just below the eye socket, according to the book "Head and Neck Surgery---Otolaryngology" by Byron Bailey. The ethmoid sinuses are located deeper and closer to the nose, but can also cause pain under the cheekbone. Pain in that area can also be due to migraine headaches, tooth infections and facial trauma.
Acute sinusitis, also known as acute rhinosinusitis, is a sinus infection that lasts less than two months. Infections that cause inflammation in the sinuses can cause sinus pain under the cheekbone, according to MayoClinic.com. The pain may be due to either inflammation or pressure in the sinuses due to fluid buildup during an acute infection.
Chronic sinusitis refers to a sinus infection that lasts more than two months or keeps coming back. According to MayoClinic.com, chronic sinusitis causes swelling around the openings of the sinuses, which causes mucus to build up inside the sinuses. The constant pressure from that mucus buildup leads to a dull pain under the cheekbones. Other symptoms may include nasal congestion, decreased sense of smell, watery eyes and swelling around the face and eyes.
Nasal polyps are pus-filled polyps that grow inside the sinuses. The polyps often result from chronic sinusitis. According to the book "Pathologic Basis of Disease" by Ramzi Cotran, the polyps do not cause any symptoms at first, but when they get larger they start to push on bone and block off the sinuses. Once they get to that point, they cause pain similar to chronic sinusitis. Ear nose and throat specialists often have to perform surgery to get rid of the polyps.
Tumors of the nose and sinuses, whether benign or malignant, can cause sinus pain under the cheekbones. The reasons why are similar to those for nasal polyps. Beside pain, sinus tumors often cause other symptoms such as bleeding, nasal blockage, decreased smell and vision changes.