Stylomastoid Foramen

The stylomastoid foramen is a curved aperture located in the middle of the base of styloid and the mastoid process of the temporal bone, on the inferior side of the petrous temporal bone. It transports the facial nerve.

Stylomastoid Foramen

Relations

• Before exiting the skull through the stylomastoid foramen, the facial nerve proceeds together with the bony canal and produces the nerve towards the stapedius as well as the chorda tympani.
• The root of the styloid process is located directly anterior towards the stylomastoid foramen as well as lateral towards the jugular foramen.

Clinical Significance

Lesions Around the Stylomastoid Foramen

The most common abnormality of the facial nerve are the lesions at and around the stylomastoid foramen and generally are caused by a viral infection of the nerve inside the bony canal prior to exiting through the stylomastoid foramen. Generally an ipsilateral motor function loss of the entire part of the face appears in the patient.

Bell’s Palsy a.k.a. Facial Nerve Palsy

The complication of the facial nerve appears as the different pathological processes and locations at which these processes appear.

The nerve may get affected by a series of lesions throughout its course, and the exact site of the lesion with respect to the course of the nerve can be determined by systematic diagnosis. Stylomastoid foramen is among commonly effected sites.