Levator labii superioris alaeque nasalis muscle

Levator labii superioris alaeque nasalis (LLSAN) muscle is traditionally thought of as a muscle of the mouth, but is also a crucial muscle of the nose, a subset of the muscles of facial expression .

Summary

Gross anatomy

Origin
  • its fibers originate from the frontal process of the maxilla, nasal bone, and medial canthus (of the eye)
Insertion
  • its muscle fibers pass inferiorly as two main components
    • alaris
      • fibers pass into the superior margin of the lower lateral nasal cartilage and skin of the alar base, intermingling with the dilator naris muscle
    • labiocolumellaris (a.k.a. labial portion)

Arterial supply

Venous drainage

Innervation

Action

  • alaris: elevator and dilator of the nostril
  • labiocolumellaris: depressor of the nostril tip

Variant anatomy

The levator labii superioris alaeque nasalis muscle is one of the more consistent muscles of facial expression, it was found without difficulty in a surgical study of forty-five cadavers .