Analysis of foramen ovale with special emphasis on pterygoalar bar and pterygoalar foramen.

ABSTRACT

The foramen ovale is of great surgical and diagnostic importance in procedures like percutaneous trigeminal rhizotomy for trigeminal neuralgia, transfacial fine needle aspiration technique in perineural spread of tumour, and electroencephalographic analysis. This study presents the anatomic variations in dimensions, appearance, number of foramen ovale (FO), and presence of pterygoalar bar and pterygoalar foramen. For the present study ninety dry adult human skulls were utilised. Anterioposterior (length) and transverse (width) diameters of FO were measured, and the presence of pterygoalar bar and foramen were observed. The most common shape of FO observed was like a figure 'D'. The ranges of anteroposterior diameter of the right and left FO were 8.5-4.5 mm and 10-3 mm, respectively. The mean length of the right FO was 6.60 mm while that of the left FO was 6.26 mm. The ranges of transverse diameter (width) of both right and left foramen were 2.5-6 mm and 2-5 mm, respectively. The mean transverse diameter of the right FO was 3.70 mm and that of left was 3.34 mm. Bony spur in FO was seen in 6.66% of cases. A complete pterygoalar bar and foramen were observed in seven cases unilaterally, and in one case it was bilateral. Anteroposterior and transverse diameters of right FO were greater than left. Anatomical understanding, including the size, shape of FO, and presence of pterygoalar bar, has immense surgical and diagnostic importance.