When present, the facial nerve is located superior and anterior to the vestibulocochlear nerve at the cerebellopontine angle and the internal auditory canal.
Image 1: Normal right vestibulocochlear nerve within the cerebellopontine angle. The loop of the anterior inferior cerebellar artery is seen anteriorly however the facial nerve is not present.
Image 2: Within the internal auditory canal, the green arrows represent the superior and inferior vestibular nerves and the blue arrow the cochlear nerve. The facial nerve is absent. The facial nerve should be located superior to the cochlear nerve and falciform crest, anterior to Bill's bar.
Image 3: Normal roots of the trigeminal nerves within the prepontine cistern.