maxillary sinus
Meaning of maxillary sinus: The maxillary sinus is the largest paranasal sinus, an air filled space within the cheekbone that drains into the nasal cavity.
Definition of maxillary sinus
The maxillary sinus is one of the paranasal sinuses, air filled spaces located within the bones surrounding the nasal cavity. A maxillary sinus sits within each maxillary bone, in the cheek area on either side of the nose, and is the largest of the paranasal sinuses.
Like the other sinuses, the maxillary sinus is lined with mucus producing tissue, and this mucus helps trap inhaled particles and moisten the air passing through the nose and sinuses before it reaches the lungs. The maxillary sinus drains into the nasal cavity through a small opening, and its position close to the roots of the upper back teeth means dental infection can sometimes spread into the sinus, and sinus disease can occasionally cause tooth pain.
Because the maxillary sinuses are enclosed, air filled spaces with a narrow drainage opening, they are prone to inflammation and fluid buildup when that opening becomes blocked, a common feature of sinus infection and allergy related sinus symptoms.
Used in a sentence
Imaging showed fluid within the maxillary sinus consistent with acute sinusitis.
Good to know
The maxillary sinus lies close to the roots of the upper back teeth, so an infection can sometimes spread between the sinus and nearby teeth in either direction, occasionally causing tooth pain to be mistaken for sinus disease or the reverse.
Word origin
Where “maxillary sinus” comes from
Formed from Latin maxilla, meaning jawbone, combined with sinus, meaning a hollow, cavity, or curve.