RESUMO
Background: Foramen Vesalius a small inconsistent foramen in the base of skull for passage of emissary vein from pterygoid plexus of veins to cavernous sinus. Variations in incidence and morphology are reported in literature. The objective of this study as to estimate its incidence in south Indian population and to evaluate the morphometric variations. Materials and Methods: Twenty-two dry skulls belonging to department of anatomy, Azeezia Institute of Medical Sciences, Kollam was studied with respect to base of the skull foramens. Wherever the foramen Vesalius was noted, the specimens were photographed and incidence, laterality was noted. Maximum, minimum and perimeter were noted. Any difference between male and female skulls and differences in right and left side were studied for statistical significance. P<0.05 was considered as significant. Results: We found foramen Vesalius in 40.9% of 44 sides examined. Six skulls had this foramen bilaterally. Three specimens had foramen Vesalius unilaterally and six specimens had it bilaterally. Average diameter of foramen was 1.35 (±0.56) mm from extra cranial aspect. The average diameter and perimeter of foramen in males were significantly lower than females. The average distance between foramen Vesalius and foramen ovale was significantly more in females than in males. Conclusion: Foramen ovale is an inconsistent and asymmetrical foramen in base of skull near foramen ovale. Forty percent of the skulls studied had foramen Vesalius. There is significant difference measurements of right and left side foramens. Considering these variations in infratemporal fossa decreases complications while approaching mandibular nerve and trigeminal ganglion.
RESUMO
Three foramina can be identified in the greater wing of the sphenoid bone: The foramen rotundum (FR), foramen ovale (FO) and foramen spinosum (FS). In addition, there may be another foramen called foramen ovale accessorium or foramen vesalius (FV) which connects the middle cranial fossa to the fossa pterygoidea (pterygoid fossa). It is described as an opening with smooth walls in front and medial to foramen ovale which leads to an oblique channel directed towards the fossa pterygoidea. FV was present between FO and FR in 14 (31.8%) of 44 dry and 6 (33.3%) of 18 cadaver skullbase sides (total 20 (32.3%) of 62). The diameter values of foramens on both the right and the left side were observed to be almost symmetrical. FR's distance from the midline on the left side was greater than the right side. Also, the distance between FO and the petrous apex and the distance between FS and the petrous apex were greater on the left side. On the right side the distance between FO and FR, and the distance between FO and FS were greater. Also, the distance between FR and the petrous apex was greater on the right side. Anatomical variations in appearance size and distance of FR, FO, FS and FV are of great surgical importance. In conclusion, we can infer that the information provided with this study can help the neurosurgeon and anatomist to increase the knowledge about anatomy of middle cranial fossa.
Tres forámenes pueden ser identificados en el ala mayor del esfenoides: El foramen redondo (FR), foramen oval (FO) y el foramen espinoso (FS). Puede además existir otro foramen llamado foramen oval accesorio o foramen de Vesalio (FV), que conecta la fosa craneal media a la fosa pterigoidea. Se describe como una abertura con paredes lisas por anterior y medial al foramen oval, que conduce a un canal oblicuo dirigido hacia la fosa pterigoidea. FV estuvo presente entre FO y FR en 14 (31,8%) de 44 cráneos secos y 6 (33,3%), en 18 lados en la base de cráneos de cadáveres (total 20 (32,3%) de 62). El diámetro de los forámenes en los lados derecho e izquierdo se observó casi simétricos. Las distancias de FR desde la línea mediana en el lado izquierdo fue mayor que en el lado derecho. Además, la distancia entre FO y el vértice de la porción petrosa y la distancia entre el FS y el vértice porción petrosa fueron mayores en el lado izquierdo. En el lado derecho la distancia entre A y FR, así como la distancia entre A y FS fueron mayores. Por otra parte, la distancia entre los FR y el vértice del porción petrosa fue mayor en el lado derecho. Las variaciones anatómicas en el tamaño de la apariencia y la distancia de FR, DE, FS y FV son de gran importancia quirúrgica. Podemos inferir que la información proporcionada en este estudio puede ayudar al neurocirujano y anatomista para aumentar el conocimiento sobre la anatomía de la fosa craneal media.