STUDIES ON THE SYMMETRY OF FORAMEN OVALE、FORAMEN SPINOSUM AND FORAMEN OF VESALIUS ON EXTERNAL BASAL SURFACE OF THE MIDDLE CRANIAL FOSSA Ⅰ. THE GENERAL AND THREE-DIMENSIONAL CONSIDERATIONS / 解剖学报

ABSTRACT

A general and three dimensional survey about the location of foramen ovale, foramen spinosum and sphenoidal emissary foramen on both sides of norma basilaris of the fossa cranialis media has been made in 100 male adult skulls collected from Shanghai region, and the following conclusions are arrived1. The foramen ovale which is located in line with the base of lateral pterygoid plate accounts for 39.5?3.46% of cases observed, and those medial and lateral to it, accounts for 57.0?3.50% and 3.50?1.30% respectively. In this respect, the skulls can be classified into two main types and eight subtypes.2. The distance from Foramen ovale to Foramen spinosum measures 3.28?0.09 mm, and from Foramen ovale to sphenoidal emissary foramen 2.23?0.11 mm.3. The frequency of occurrence of the sphenoidal emissary foramen is 42.5% in 200 sides (40% to the left and 45% to the right), and in 28% of the 100 skulls this foramen occurs bilaterally.4. The long diameter of foramen ovale ranges from 3.8 to 12.0 mm, with 7.21?0.08 mm as the average, side difference is not significant statistically in the 4 major subtypes. The angle between this same long diameter and the sagittal plane running through theintermaxillary suture varies from 39? to 85?, with a mean of 55.08??0.61?; and again, no significant side-difference can be found.The average width of foramen ovale is 3.85?0.05 mm (2.3～6.5 mm); and significant side-difference exists between types Ⅰ_A and Ⅱ_A, the difference is more prominant on the left side than on the right. 5. In spite of the side difference of the three dimensional values of all the three foramina being insignificant statistically in most subtypes, the following instances, however, are worth noting (1) right foramen ovale in Ⅰ_A and Ⅱ_A subtypes locates further away form the frontal plane which traverses the prosthion than the corresponding froamin on the left side (t=3.70, P