A morphometric study of stylomastoid foramen with its clinical applications

Background To prevent damage to the facial nerve while doing surgery and to give facial nerve block by anesthetics near the stylomastoid foramen we should know its distance from the important anatomical landmarks. So, this study aims to study the location of stylomastoid with respect to nearby anatomical landmarks. Materials and Method The study was performed on 58 dry skulls. Measurements of stylomastoid foramen were taken from various anatomical landmarks on both sides of the skull. Data analysis was done by using the Statistical Package for Social Sciences (SPSS) 19 version. Results The mean distance of the center of the stylomastoid foramen (CSMF) to the tip of the mastoid process was 1.60, 1.57 cm on the right and left side, respectively. The mean distance of CSMF to the upper end of the anterior border of the mastoid process was 1.42, 1.39 cm on the right and left side, respectively. The mean angle between CSMF and tip of the mastoid process was 51.6 degrees, 53.5 degrees on right and left side, respectively. The mean distance of CSMF to the center of jugular foramen was 1.27, 1.26 cm on the right and left side, respectively. The position of the stylomastoid foramen in relation to a transverse line passing through the upper end of the anterior border of both mastoid processes was anterior in 82.7%, 94.8% of cases on the right and left side, respectively. Conclusion These measurements will aid neurosurgeons in doing surgeries near the stylomastoid foramen or anesthetics to give facial nerve block near the foramen.