Prevalence and anatomical variations of maxillary sinus septa: A cone-beam computed tomography analysis

BACKGROUND: Detailed understanding the anatomy and variations of maxillary sinus septa is necessary. We aimed to investigate prevalence and various anatomical variations of maxillary sinus septa using cone-beam computed tomography (CBCT) images. MATERIAL AND METHODS: In this retrospective cross-sectional study, CBCT scans of 809 patients referred to a specialist dental and maxillofacial radiology clinic in Babol, northern Iran, during 2014-2020 were evaluated. Location, morphology, height, and direction of septa in different planes were recorded. RESULTS: Sinus septa were observed in 37.9% (n=307) of the participants. There were 117 cases with septa only in left sinus, 83 cases with septa only in right sinus, and 107 cases with septa in both sinuses. Totally, 414 septa were seen in the subjects. Prevalence of partial septa was considerably higher than complete septa (77.5% versus 22.5%). Regarding septa location, middle area with a prevalence rate of 58.7% was found more prevalent than other sinus areas. The mean septum height on the left and right sinuses was 6.0±3.1 mm 5.7±3.9, respectively (p<0.001). Regarding left sinus, directions of vertical (63.8%), oblique (30.8%), and straight (63.8%) were the most prevalent compared with other directions in sagittal, frontal, and axial planes, respectively. In relation to right maxillary sinus, direction of vertical in sagittal and frontal planes (72.6% and 24.2%, respectively), and direction of straight in axial plane (58.4%) were the most prevalent directions compared with others in the same planes. CONCLUSIONS: Septa prevalence in maxillary sinus was relatively high, with various directions, locations, heights, and shapes. It is recommended to use CBCT for a careful evaluation of toothless area prior to surgeries on the sinus (especially sinus lift) in three plans, in order to take careful measures and prevent postoperative complications in case septa exist. Key words:Maxillary sinus septa, anatomical variation, cone-beam computed tomography, dental implant.