Foramen Meningo-orbitale and its relationship with the middle meningeal artery

Foramen meiningo-orbitale, a solitary canal for a branch of the middle meningeal artery is a embyological variant during an ophthalmic artery development. The anastomotic pattern between the internal and external carotid artery is different according to the foramen. In Korean, there has been no report on the foramen meningo-orbitale, but also on the anastomosis between the middle meningeal and the ophthalmic arteries. The incidence and location of the foramen meningo-orbitale are reported from fifty korean adult dried skulls and the anastomotic pattern of the middle meningeal artery in thirty orbits is also reported. The foramen meningo-orbitale was presented in 45% of the cases. It appeared in both side at the same person in 38%. Double foramen was observed in 9% of the cases. The foramen located on the superior lateral aspect of the greater wing of the sphenoid bone and the average distance from the lateral angle of the superior orbital fissure was 6.1±4.7 mm. The impression forming on the lateral margin of the superior orbital fissue was identified in 18% of the cases. The meningolacrimal artery was found in 50% of the dissected materials. It entered the orbit through the foramen meningo-orbitale and gave off the lacrimal artery. In these cases, there was no anastomosis between the lacrimal and the ophthalmic arteries. The recurrent meningeal artery was observed in 33.3% and it formed an anastomosis between the lacrimal and the middle meningeal arteries in the cases which had no meningolacrimal artery. In 13.3%, two lacrimal artery were observed, in which one arose from the ophthalmic artery and the other from the meningolacrimal or sphenoidal artery. In one case, the meningolacrimal artery and the meningoophthalmic artery co-existed. We discuss them embryologically.restrictio