Levator Labii Superioris Alaeque Nasi

Facial Expression · Head & Neck

Levator Labii Superioris Alaeque Nasi belongs to the Facial Expression group of the Head & Neck. Originating at Frontal process of the maxilla, it inserts at Skin of the lateral nostril (alar cartilage) and the upper lip. Its chief action is that it dilates the nostril and elevates the upper lip and the ala of the nose. Its nerve supply is the Buccal and zygomatic branches of facial nerve (CN VII).

Origin, Insertion, Action & Nerve

Origin

Frontal process of the maxilla

Insertion

Skin of the lateral nostril (alar cartilage) and the upper lip

Action

Dilates the nostril and elevates the upper lip and the ala of the nose

Nerve

Buccal and zygomatic branches of facial nerve (CN VII)

Attachments explained

The Levator Labii Superioris Alaeque Nasi is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.

Origin

Frontal process of the maxilla

Insertion

Skin of the lateral nostril (alar cartilage) and the upper lip

Action & function

When the Levator Labii Superioris Alaeque Nasi contracts, it produces the following movement: Dilates the nostril and elevates the upper lip and the ala of the nose.

As part of the Facial Expression group of the Head & Neck, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.

Nerve supply & clinical relevance

The Levator Labii Superioris Alaeque Nasi receives its nerve supply from the Buccal and zygomatic branches of facial nerve (CN VII).

Because a muscle can only contract when its nerve is intact, injury to the Buccal and zygomatic branches of facial nerve can weaken or paralyse the Levator Labii Superioris Alaeque Nasi, impairing the movements it normally produces (dilates the nostril and elevates the upper lip and the ala of the nose). This is why knowing the innervation is central to localising nerve lesions in clinical practice.

How to study the Levator Labii Superioris Alaeque Nasi (the OIANS method)

OIANS stands for Origin, Insertion, Action and Nerve, the four facts that uniquely define every skeletal muscle. To learn the Levator Labii Superioris Alaeque Nasi, work through them in order: picture its origin, trace the muscle to its insertion, reason out the action that shortening between those two points must create, then add the nerve that drives it.

Most students remember the Levator Labii Superioris Alaeque Nasi fastest by linking its action back to its attachments rather than memorising each fact in isolation. Once the origin and insertion make sense, the action usually follows logically.