Prevalence, location, and size of maxillary sinus septa: panoramic radiograph versus computed tomography scan.

Purpose: To determine the prevalence, location, and size of maxillary sinus septa, and to compare the results of panoramic radiographs and computed tomography (CT) scans.
Materials and Methods: This study included 30 patients, 17 women and 13 men, with a mean age of 50.9 years (range, 28-73 years), undergoing treatment planning for implant-supported restorations in the maxilla. Three observers analyzed the panoramic radiographs, the conventional CT scans in acetate, and the Implametric 3-dimensional CT (3Dent, Valencia, Spain). The maxillary sinus septa of each patient and the type of septa, as well as its location and size, were recorded.
Results: In 60 maxillary sinuses, panoramic radiographs showed 32 septa (53.3%); CT in acetate showed 42 septa (70%); and Implametric 3-dimensional CT showed 40 septa (66.7%). Most septa (60%) were located in the middle region of the maxillary sinus, 22.5% in the posterior region, and 17.5% in the anterior region. The mean height of the septa was 4.78 ± 1.76 mm. Panoramic radiographs led to an erroneous diagnosis in 46.5% of the cases.
Conclusions: Maxillary sinus septa are a frequent anatomic variation. They can be found in any of the maxillary sinus regions independently of patient edentulism. The panoramic radiograph can lead to false-positive and false-negative findings in the visualization of septa in almost half of cases. Therefore, whenever a maxillary sinus lift is planned, a thorough study of the affected sinus should be made using CT.
(Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)