The residual bone height in the posterior edentulous maxilla is frequently limited by the maxillary sinuses. Sinus floor elevation (SFE) is then considered to restore sufficient bone height. The preoperative analysis of the maxillary sinus is necessary for the success of this surgery. Therefore, we investigated the frequency of maxillary sinus anatomic variations and lesions by using cone beam computed tomography (CBCT).

We retrospectively analysed all CBCTs performed at a private radiological center between January and November 2014. The following anatomical variations and lesions were assessed: sinus ventilation, sinus septa, the sinus totally compartmentalized, the hypoplastic sinus, sinus aplasia, the prolapsed sinus, thickness of the anterolateral wall, the position of antral artery, mucosa thickening, sinus opacity, the polyps and the cysts.

A total of 300 cone beam images were analyzed. The findings consisted in: ventilation 91%, septa 34.66%, total compartmentalized sinus 6%, hypoplastic sinus 5%, aplastic sinus 0%, prolapsed sinus 1.66%, endorsed position of the antral artery 53%, submucosa position 43%, thickening of the sinus mucosa 41%, sinus opacity 4%, polyps and the cysts 20.33%. The average thickness of the anterolateral wall was about 1.16±0.48mm.

The maxillary sinus has great interindividual anatomical variability. The cone beam is highly beneficial for the analysis of the anatomical structures in relationships with any sinus surgery.