Posteroinferior septal defect due to vomeral malformation.

Purpose: Vomeral malformation may lead to a posteroinferior septal defect (PISD). It is usually found incidentally, without any characteristic symptoms. The purpose of this study was to evaluate its clinical implications.

Methods: In this study, we included 18 patients with PISD after reviewing paranasal sinus computed tomography scans and medical records of 2655 patients. We evaluated the shape of the hard palate and measured the distances between the anterior nasal spine (A), the posterior end of the hard palate (P), the posterior point of the vomer fused with the palate (V), the lowest margin of the vomer at P (H), and the apex of the V-notch (N).

Results: None of the PISD patients had a normal posterior nasal spine (PNS). Six patients lacked a PNS or had a mild depression (type 1 palate), and 12 had a V-notch (type 2 palate). The mean A-P, P-H, and P-V distances were 44.5 mm, 15.3 mm, and 12.4 mm, respectively. The average P-N distance in patients with type 2 palate was 7.3 mm. There were no statistically significant differences between the types of palates in A-P, P-H, or P-V distances. In patients with type 2 palate, there was a significant correlation between P-V and P-N distances (r = 0.664, p = 0.019).

Conclusions: PISD due to vomeral malformations was identified in 0.7% of the cases in this study. None of the subjects had a normal PNS, which suggests that the development of the vomer is closely related to that of the hard palate.