The meningo-orbital foramen: Incidence in dry human skulls and clinical relevance

Katti, Karuna and Ali, Naila (2024) The meningo-orbital foramen: Incidence in dry human skulls and clinical relevance. Journal of Anatomy, 245 (2): 09. p. 350. ISSN 0021-8782

Abstract

When present, the meningo-orbital foramen (MOF) communicates the orbit with the cranial cavity and may transmit a branch of middle meningeal artery supplying the orbit (meningo-lacrimal artery). The present study was conducted to review the detailed morphometry of MOF, to discuss its clinical significance and exact location for navigation during orbital surgery. One hundred and twenty-seven dry adult human skulls (254 orbits) in the Human Anatomy Unit at University of Birmingham were studied. Unfortunately, the ethnicity and sex of these skulls were unknown. The sex was estimated using standard craniofacial morphology traits. Incidence of the patent MOF was recorded bilaterally and variations in location and communication were noted for male and female sex. The mean distance of MOF from the frontozygomatic suture was recorded bilaterally. The overall incidence of patent MOF was 36% (in 92 orbits out of 254). The incidence was slightly higher in females. In ~50% cases, the MOF was located in greater wing of sphenoid. In 27 skulls (54 orbits), it was seen bilaterally. Eight orbits showed the presence of an extra MOF either unilaterally or bilaterally. Only 1 orbit had a triple foramina. More than 95% MOF communicated with middle cranial fossa. The mean distance between the MOF and the frontozygomatic suture on the lateral orbital margin was greater in males (On right side: 24.71 mm in females and 25.16 mm in males. On left side: 24.10 mm in females and 26.52 mm in males). As the MOF can transmit a lacrimal branch from the middle meningeal artery, awareness about the variable presence and location of MOF is important for surgeons to avoid injury to the vessel. We suggest further exploration of MOF and course of meningo-lacrimal artery if present by cadaveric dissection. Ethics statement: All of these skulls are existing holdings with permission for research in the Human Anatomy Unit at the University of Birmingham under the HTA license number 12236.