The superior meatus occupies the middle third of the nasal cavity’s lateral wall.

Through the hiatus semilunaris the meatus communicates with a curved passage termed the infundibulum, which communicates in front with the anterior ethmoidal cells and in rather more than fifty percent of skulls is continued upward as the frontonasal duct into the frontal air-sinus; when this continuity fails, the frontonasal duct opens directly into the anterior part of the meatus.

Below the bulla ethmoidalis and hidden by the uncinate process of the ethmoid is the opening of the maxillary sinus (ostium maxillare); an accessory opening is frequently present above the posterior part of the inferior nasal concha.

It is broader in the front than at the back, and presents anteriorly the lower orifice of the nasolacrimal canal.

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)