Morphometric Analysis of the Foramen Ovale and Its Clinical and Surgical Implications

Abstract

Background: The foramen ovale (FO) is an opening at the posterior part of the greater wing of the sphenoid bone. Prior knowledge of the topography and possible variations in FO morphometry prevents possible injuries to the trigeminal nerve during such approaches. Aim: To analyze FO morphometry and its clinical and surgical implications. Materials and methods: 72 dry adult male and female human skulls were used. Skulls were measured bilaterally using a Stainless® digital caliper with a capacity of 150 millimeters. The following variables were analyzed: anteroposterior diameter (length); transverse diameter (width); distance from the FO center to the tubercle of the zygomatic root (d 1 ); and the distance from the FO center to the midline of the skull base (d 2 ). Results: The mean length in male skulls was 7.58 ± 1.05 mm on the right side and 7.77 ± 1.24 mm on the left side, whereas in females it was 7.56 ± 1.79 mm and 7 .97 ± 1.58 mm, respectively. Regarding the mean width values, it was observed that the measurements in males were predominantly higher when compared to females. The distance from the FO center to the tubercle of the zygomatic root (d 1 ) presented higher mean values in male skulls, whereas the distance from the FO center to the midline of the skull base (d 2 ) was predominantly greater in the right side when compared to the left side in females. Conclusion: Variations in FO size and shape are common findings, and they are likely related to fetal development. Thus, a thorough knowledge of FO morphological variants and morphometric details is greatly important for the diagnosis and treatment of several conditions, when microneurosurgical and microvascular approaches are necessary.