Structure/Morphology
The modiolus of angulus oris is a fibromuscular region of the orbicularis oris that sits lateral to the angles of the mouth (i.e., the border between the upper and lower lips) (Standring, 2016).
Anatomical Relations
The modiolus of angulus oris receives innervation from the buccal and mandibular marginal branches of the facial nerve (CN VII). It receives its arterial supply from the superior and inferior labial arteries.
Function
The modiolus of angulus oris is the site of insertion for several muscles of facial expression, including the buccinator, zygomaticus major, levator anguli oris, depressor anguli oris, orbicularis oris, and risorius. This arrangement allows these muscles to integrate the movements of the cheeks, lips, oral fissure and cavity, and jaws.
List of Clinical Correlates
- Bell’s palsy
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
