摘要
foramen venosum (foramen vesalius) is an inconstant structure which is located posterior to the foramen rotundum and medial to the foramen ovale, and it gives pace to an emissary vein that communicates the plexus pterigoideus and the sinus cavernosus. the existence of this anatomical structure can be of interest in certain procedures like percutaneous trigeminal rhizotomy where this foramen can be the cause of a false pathway and be punctured causing a subdural hematoma. it also can be an access to the sinus cavernosus for infected thrombus coming from dental and facial infections. for this study the skull collection of the anatomy department, faculty of medicine uanl, was used. we observed the frequency and measured the following parameters: length and width; in the basis cranii we measured: distances to the foramen rotundum, foramen ovale, planum medianum and between two foramina venosum (one on each side). in basis cranii externa we measured: distances to foramen ovale, planum medianum, and between two foramina venosum. three independent observers blinded among them, measured the parameters using a vernier and microphotographs with milimetrical scales. a 20% frequency was found and the following median measures: length 1.66mm, width 1.06mm; basis cranii: distance to foramen rotundum 11.31mm, distance to foramen ovale 4.13mm, distance to planum medianum 17.75mm and 31.91mm between both foramina venosum. basis cranii externa: distance to foramen ovale 2.49mm, distance to planum medianum 19.54mm and distance between foramenina venosum 36.05. the distance to the foramen ovale varies between basis cranii and basis cranii externa because the foramen has an oblique trajectory and it approximates to the foramen ovale (from superior to inferior) and separates from the planum medianum. it was found bilaterally only in one skull. there are differences between the left and right foramens, the latter being generally larger.