Sphenovomerine suture: a useful landmark for locating sphenoid sinus ostium.

Aim: The aim of this study was to determine whether the sphenovomerine suture (SVS) can be used as a landmark to localize the sphenoidal sinus ostium.

Methods: Endoscopic imaging was done on 152 skulls to identify ostium of the sphenoidal sinus, the SVS, and the articulation of sphenoidal process of palatine bone between the body of the sphenoid and the sphenopalatine foramen. The variables were as follows: (1) the distance between the medial border of the ostium and SVS (DSO-SVS); (2) the angle between them (ASO-SVS); (3) the distance between the inferior border of the ostium and the horizontal line (DSO-HL); (4) the distance between intersection point of the SVS-sphenoidal process of the palatine bone and the medial border of sphenopalatine foramen (DSPF-SVS); and (5) the number of sphenopalatine foramen.

Results: Of the 152 skulls, 289 sides were included in the study. The mean value for DSO-SVS was 3.15 (1.35) mm, DSO-HL was 5.99 (2.38) mm, DSPF-SVS was 7.07 (1.96) mm, and ASO-SVS was 5.99 (9.73) mm. As DSPF-SVS decreases, DSO-SVS and DSO-HL decrease with statistical significance (Ps = 0.02 and 0.001, respectively). The distribution of the numbers of sphenopalatine foramen was as follows: one 90%, two 9.7%, and four 0.3%.

Conclusions: The horizontal distance between the SVS and the sphenopalatine foramen plays a significant role in identifying the location of sphenoid sinus ostium. As with the other landmarks, the SVS provides an additional benefit in locating the sphenoid sinus ostium for endoscopic sinus surgeons. The incidence of 4 sphenopalatine foramen is 0.3%.