A Cadaveric Study of the Cranio-orbital Foramen and Its Significance in Orbital Surgery

BACKGROUND: The cranio-orbital foramen is an osseous anatomical landmark located adjacent to the superior orbital fissure. It is a potential source of hemorrhage during deep orbital dissection because it is the location of an anastomosis between the lacrimal artery and the middle meningeal artery. The purpose of this study was to determine the incidence, location, and number of cranio-orbital foramina within a Caucasian population. METHODS: Forty-seven orbits from 24 formalin-fixed Caucasian cadavers were exenterated. If the cranio-orbital foramen was present within an orbit, its distance from the frontozygomatic suture, supraorbital notch, and Whitnall's tubercle was measured. The gender variations and asymmetric presentations of foramina were studied. RESULTS: The cranio-orbital foramen was present in 26 orbits (55 percent). The average distance from the frontozygomatic suture, supraorbital notch, and Whitnall's tubercle was 30.92 mm (±4.37 mm), 37.77 mm (±3.55 ±), and 29.69 mm (±3.89 mm), respectively. In nine orbits (19 percent), an additional accessory cranio-orbital foramen was identified. The average distance from the frontozygomatic suture, supraorbital notch, and Whitnall's tubercle was 28.56 mm (±5.00 mm), 32.64 mm (±3.20 mm), and 27.78 mm (±5.24 mm), respectively. CONCLUSION: The presence of the cranio-orbital foramen and other accessory foramina represents a source of hemorrhage that surgeons should be aware of when operating along the lateral orbital wall.