The sinus septi nasi and other minor pneumatizations of the nasal septum.

The osseous nasal septum (NS) consists of the perpendicular plate of the ethmoid bone (PPE) and the vomer bone. Few studies evaluated the possibilities of septal pneumatization of the PPE, or adjacent to it. We aimed to observe the anatomical possibilities of NS pneumatizations. A retrospective lot of cone-beam computed tomography (CBCT) files was used. One hundred seventy-one CBCT files from 51 males and 120 females were documented. There were found 46 files that were null for septal pneumatization. The other cases (73.1%) had different septal pneumatizations extended from neighboring air spaces. Pneumatized crista galli (CG) exclusively extended from a frontal sinus was found in 7.01% of cases. The frontal sinuses had minor extensions anterior to the PPE in 7.6% of cases. Unique or double pneumatizations of the sphenoidal rostrum extending within the posterior part of the PPE were detected in 71.34% of cases. In six cases were found ethmoidal pneumatizations of the PPE, either from an anterior ethmoid cell, or from a posterior one, or from a pneumatized CG. In this last case was found a sinus septi nasi of 25.37 mm sagittal size. The supra-septal recesses of the ethmoid air cells were roofing the respective nasal fossa. As all the morphological possibilities of NS pneumatization involve the upper part of the PPE, they should be adequately discriminated anatomically, as well as when the NS and the cribriform plate of the ethmoid bone are approached surgically.