Morphometric Analysis of Stylomastoid Foramen and its Clinical Significance/Analisis Morfometrico del Foramen Estilomastoideo y su Importancia Clinica

The stylomastoid foramen is located on the inferior surface of the petrous part of the temporal bone between the base of the styloid process and mastoid processes. Through the stylomastoid foramen the facial nerve completes its intracranial part. The aim of this study was to analyze the morphometric parameters, shape and position of the stylomastoid foramen on the skulls in Serbian population, and to correlate it with gender and body side. The study included 44 dry adult skulls (88 stylomastoid foramen). After we determined the gender, the skulls were photographed, and then distances of the stylomastoid foramen from various important landmarks of the skull base were measured in programme ImageJ. The shape and position of the stylomastoid foramen were also noted. The statistical significance was found in male skulls between right and left side in relation to parameter (P2) the shortest distance from the upper end of the anterior margin of the mastoid process (MP) to the center of stylomastoid foramen (CSMF), and on the left side for parameter (P6) the shortest distance between CSMF and the line passing through the tip of the MP in relation to gender. The most common shape of the stylomastoid foramen was round in 46 (52.27%) cases, and most common position was on the line passing through the upper end of the anterior margin of both MP in 36 (40.91%) and medially to the line connecting the tips of the MP and styloid process in 88 (100%) cases. The results of this study will be useful for neurosurgeons during surgeries on the facial nerve trunk or anesthetics to give facial nerve block near the foramen and prevent its complications.