The maxillary sinus is the largest of the paranasal sinuses and is located in the maxilla, lateral to the nasal cavity and inferior to the orbit. The maxillary sinus opens into the posterior aspect of the hiatus semilunaris in the middle meatus. The infraorbital nerve (CN V-2) primarily innervates the maxillary sinus.
results from inflammation of the mucous membrane lining the maxillary sinus and is a common infection because of its pattern of drainage. The maxillary sinus drains into the nasal cavity through the hiatus semilunaris
, which is located superiorly in the sinus (Figure 23-2C
). As a result, infection has to move against gravity to drain. Infection from the frontal sinus and the ethmoidal air cells potentially can pass into the maxillary sinus, compounding the problem. In addition, the maxillary molars are separated from the maxillary sinus only by a thin layer of bone. Therefore, if an infecting organism erodes the bone, infection from an infected tooth can potentially spread into the sinus. The infraorbital nerve (CN V-2)
innervates the maxillary teeth and sinus; therefore, pain originating from a tooth or the sinus may be difficult to differentiate.