Background: The aim of our study was to investigate, in 3 dimensions, the maxillary sinus septa as an alternative site for dental implant placement to avoid sinus lift procedures. Material and Methods: We selected 100 dentate and 100 edentate patients with the presence of a maxillary sinus septum by reviewing a larger cone beam computer tomography (CBCT) database from the Department of Oral and Maxillofacial Surgery at Cliniques Universitaires Saint Luc in Bruxelles, Belgium. Three-dimensional reconstructions of 200 maxillary sinus septa were performed using Maxilim software. Ten measurements (length, lateral height, and thickness of the middle and medial region of the septum) were performed by 1 observer, 2 times, with an interval of 1 week between measurements. The angle between the septum and the maxillary plane was also measured. Finally, localization and orientation were assessed for each septum. Results: There was no statistically significant difference between the 2 intraobserver measurements (p>0.05). Student’s t-test was used to compare means. Middle height was the only measurement for which there was a difference between edentate and dentate patients (p=0.0095, edentate mean < dentate mean). The location of the septa observed in our study groups demonstrated greater prevalence in the posterior region than in the anterior and middle regions. For the spatial orientation of the septum, we found that most septa (81.2% in dentate patients, 53% in edentate patients) were oblique. Conclusions: Three-dimensional evaluation of maxillary sinus septa using 3D CBCT imaging showed that the sinus septum could offer an alternative site for implant placement in the maxillary sinus.

Keywords: Cone-Beam Computed Tomography, Dental Implants, Sinus floor augmentation