Facial nerve inflammation in the stylomastoid foramen may cause Bell's palsy.

The stylomastoid foramen is between the styloid and mastoid processes of the temporal bone.

[3] Bell's palsy can result from inflammation of the facial nerve where it leaves the skull at the stylomastoid foramen.

Patients with Bell's palsy appear with facial drooping on the affected side.

This article incorporates text in the public domain from page 144 of the 20th edition of Gray's Anatomy (1918)