Morphometric Analysis of the Supraorbital and Infraorbital Foramina Based on the Medial Canthus in Koreans

Lee, Myoung Hwa; Jeong, Goosoo; Yu, Sun Kyoung; Lee, Kwang Young; Kim, Seog; Lee, Dong Seol; Kim, Heung Joong

Abstract

Knowledge of the location of the maxillo-facial foramina is essential for regional nerve blocks and endoscopic surgical procedures to avoid nerve injury passing through these foramina. The purposes of this study were to determine the locations of the supraorbital foramen (SOF) and the infraorbital foramen (IOF) related to medial canthus (MC), and to analyze the morphology of these foramina. Thirty-two embalmed cadavers (64 sides, mean age: 64.1 years) and 33 dry skulls (66 sides) were used. The distances from the SOF, IOF, and MC to facial midline were directly measured on the cadavers using digital Vernier caliper. The vertical and horizontal distances of the SOF and IOF relative to the medial canthus were indirectly measured on the digital photographs using image analyzer software. The vertical and horizontal diameters of the IOF, and its location in relation to maxillary tooth were evaluated on the dry skull. Statistical analysis was performed using one-way ANOVA with declaration of significant difference when P<0.05. The mean distances of SOF, MC, and IOF to the facial midline were 24.13 mm, 15.00 mm, and 29.11 mm, respectively. The SOF was located 18.99 mm superior and 9.05 mm lateral to the medial canthus. The distance between the medial canthus and the SOF was 22.67 mm, and the vertical angle (Angle 1) between these structures was 24.36degrees superolaterally. The IOF was located 26.69 mm inferior and 13.53 mm lateral to the medial canthus. The distance between the medial canthus and IOF was 30.82 mm and the vertical angle (Angle 2) between these structures was 26.59degrees inferolaterally. In the this study, spraorbital notch (SON) was found more frequently than the SOF. The mean vertical and horizontal diameters of IOF were 3.36 mm, 3.45 mm, respectively. IOF was most commonly found in the same vertical plane with the second upper premolar. In conclusion, these results are important for performing local anesthetic, facial plastic surgery, and other invasive procedures in the forehead and periorbital region to prevent injury of neurovascular bundles passing through these foramina.