CBCT Study of Morphologic Variations of Maxillary Sinus Septa in Relevance to Sinus Augmentation Procedures

Augmentation of the maxillary sinus increases the lost height of ridge in the posterior maxilla. Bony convolutions from the floor of the sinus called septa may be encountered during the procedure and significantly impact the outcome of the procedure.

For this retrospective study, 120 cone-beam computed tomography (CBCT) scans were collected from the archives of the department of oral radiology in the time period between January 2016 and August 2018. Planmeca Romexis^® software version 3.2.7 was used to check for the incidence, and then among the septa, plane of orientation, location with respect to the wall of the sinus, and in terms of relation to tooth were examined. The average height and average width of all the septa were measured using a measuring tool in the software.

Thirty-five of the total 88 patients showed septa in 40 sinuses, in which 36 sinuses showed one septum and 4 sinuses showed 2 septa. Forty-one septa were located on the floor of the sinus in the frontal orientation and 3 septa were located on the lateral wall of the sinus in the axial orientation. The mean height and mean width of the 41 septa on the floor of the sinus were 5.72 mm and 3.47 mm, respectively. The mean height of septa found on the lateral wall of the sinus was 5.59 mm.

Septa had a higher tendency to be in bucco-palatal direction and on the floor of the sinus and frequent occurrence in the region of molars. A thorough prediagnostic evaluation using CBCT is necessary prior to sinus augmentation procedures.