Maxillary sinus septa: a 3-dimensional computerized tomographic scan analysis

The purpose of this study was to determine the prevalence, size, location, and morphology of maxillary sinus septa in dentate, partially dentate, and edentulous maxillae.

Data from 312 sinuses were analyzed from reformatted computerized tomograms utilizing SIM/Plant software. The sample consisted of 156 patients (106 women and 50 men, with ages ranging between 24 and 86 years and a mean age of 55.4 years) who were being treatment-planned to receive implant-supported restorations.

A total of 75 septa were found in 312 maxillary sinuses (24%), which corresponded to 32.7% of the patients (51 of 156). Completely edentulous patients presented with 33.3% of the total septa, while 66.7% of the septa were identified in partially edentulous patients. Analysis of the anatomic location of the septa within the sinus revealed that 18 (24.0%) septa were located in the anterior region, 31 (41.0%) were in the middle, and 26 (35.0%) were in the posterior region. Measurements of height of the septa varied among different areas. The lateral area ranged from 0 to 15.7 mm (with a mean of 3.54 +/- 3.35 mm), the middle area ranged from 0 to 17.3 mm (with a mean of 5.89 +/- 3.14 mm), and the medial area ranged from 0 to 20.6 mm (with a mean of 7.59 +/- 3.76 mm). A total of 20 septa (26.7%) were located in the immediate apical region of teeth. The remaining 55 septa (73.3%) were related to edentulous areas.

Septa may arise in any of the 3 regions of the maxillary sinus irrespective of the degree of dentulism or edentulism present.

To avoid unnecessary complications during sinus augmentation procedures, adequate and timely identification of the anatomic structures inherent to the maxillary sinus are required.