Falciform crescent

Dr Jeremy Jones et al.

The falciform crescent is a horizontal ridge that divides the internal acoustic meatus into superior and inferior portions.


The facial nerve and superior vestibular nerve (SVN) travel in the superior portion of the IAM with the facial nerve anterior to the SVN and separated from it in the lateral portion by Bill's bar, a vertical ridge of bone.


The cochlear nerve and inferior vestibular nerve (IVN) run inferior to the falciform crescent with the cochlear nerve situated more anteriorly.

Head and neck anatomy
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Article information

rID: 4518
System: Head & Neck
Section: Anatomy
Tag: refs
Synonyms or Alternate Spellings:

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Cases and figures

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    Nerves of the internal acoustic meatus (diagram)
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