The morphology and morphometry of the so-called "meningo-orbital foramen" in humans

The so-called meningo-orbital foramen creates an additional link between the orbit and the cranial cavity. This bony canal, not always present in the human skull, contains a branch from the middle meningeal artery, providing an accessory blood supply to the orbit. This vessel, like the foramen, is characterised by great variability. Although older textbooks of basic anatomy suggested that it was a rare occurrence, some current data indicate a more frequent incidence of this foramen. These discrepancies were verified in our research. 92 orbits were studied on 46 macerated human skulls (25 male and 21 female). Although the incidence of the meningo-orbital foramen in the material as a whole was 28%, the foramen in female skulls was observed to be 40.5%, compared to 18% in male skulls. This difference was statistically significant. A double foramen was encountered in three orbits, and in one orbit there was a triple foramen. This means that in the material as a whole multiple foramina were observed in 4% of cases. Two measurements were taken to determine the localisation of the meningo- orbital foramen. The minimal distance between the supraorbital notch (or foramen) and the meningo-orbital foramen was 35.0 (28–44) mm. The minimal distance from the cross-point of the entrance to the orbit and the fronto-zygomatic suture was (21.3-35.5) mm. This indicates that the meningo-orbital foramen can lie near an operating field in some surgical interventions through the lateral orbital wall

Analysis of operating field area in transpyramidal retrolabyrinthine approach to posterior cranial fossa

Retrolabyrinthine surgical access to the posterior and middle cranial fossa has a long history of use during the procedures aiming at the removal of small neoplasmatic changes located in the area of the internal auditory tube. A precise knowledge of the anatomical alterations of the temporal bone in the aspect of the retrolabyrinthine access to the posterior cranial fossa determines a successful otoneurosurgical endoscopy, which involves a relatively narrow area. Fortyfour cadaver temporal bones of both sexes were measured to obtain the dimensions of the surgical area limited by the sigmoid sinus, superior petrosal sinus and posterior labyrinth. The techniques of computer picture analysis were applied in the research. The mean value of the surface area of the figure limited by the sigmoid sinus, superior petrosal sinus and posterior semicircular canal was 175.9 mm² with no significant differences between sexes and sides. The maximal measured value was 356 mm², and the minimal was 84.3 mm². The size of the surgical area is characterised by large deviation range but was always sufficient to insert the endoscopic device and standard otosurgical instruments