Surgical anatomy of orbital apertures

Abstract

Objective: To determine the distances from the constant landmarks on the orbital rim to the orbital apertures and to investigate the gender and side differences in those distances. Materials and methods: The distances from the constant landmarks on the orbital rim to the orbital apertures were measured in 100 orbits from 50 adult human dried skulls (25 females and 25 males). The measurement of each distance was done by using electronic caliper. The data was analyzed by descriptive statistics as means and standard deviations. Comparison between genders and sides for each measurement was done by student's t-test Results: The average distances for each wall of orbit were reported. On the medial wall, the distance from the midpoint of the anterior lacrimal crest to anterior ethmoidal foramen was 23.49 ± 2.64 mm and to the medial aspect of optic canal was 42.18 ± 2.33 mm. The only 15 % of the anterior ethmoidal foramina were located superiorly to frontoethmoid suture line at the distance of 1.95 ± 0.70 mm. On the roof, the distance from supraorbital foramen to the closest margin of superior orbital fissure was 40.01 ± 2.36 mm and to the superior aspect of optic canal was 44.65 ± 2.33 mm. On the floor, the distance from the orbital rim above infraorbital foramen to the closest margin of inferior orbital fissure was 21.67 ± 1.96 mm and to the inferior aspect of optic canal was 46.19 ± 2.78 mm. On the lateral wall, the distance from the frontozygomatic suture to the closest margin of superior orbital fissure was 34.50 ±2.55 mm and to the lateral aspect of optic canal was 46.91±2.38 mm. The lacrimal foramen could be found in 37 orbits. There were some gender and side differences. Related to the gender, there were significant differences on the distance from the frontozygomatic suture to the closest margin of inferior orbital fissure in the left orbit. And in the right orbit, the differences were found in the distances from the midpoint of the anterior lacrimal crest to the posterior lacrimal crest, from the supraorbital foramen to the closest margin of superior orbital fissure and to the superior aspect of optic canal. Related to the side in independence of gender, there were significant differences on the distance of the followings: from the midpoint of the anterior lacrimal crest to the posterior lacrimal crest, the anterior & posterior ethmoidal foramina, from the supraorbital foramen to the lacrimal foramen and from the frontozygomatic suture to the closest margin of inferior orbital fissure and to the lateral aspect of optic canal. Conclusion: There were significant differences in some distances in comparison between genders and sides. These data should be concerned when the orbital and periorbital surgeries are to be done. Moreover, these results are also useful for human anthropological study, especially in Asian population.