Levator labii superioris alaeque nasi: anatomy
- Muscle
Quick facts
- Origin
- Frontal process of the maxilla, beside the root of the nose.
- Insertion
- Medial slip into the alar cartilage and skin of the nostril wing; lateral slip into the upper lip.
- Action
- Lifts the upper lip and flares the nostril, as in the expression of disgust.
- Innervation
- Zygomatic and buccal branches of the facial nerve.
- Relevance in facial harmonization
- Takes part in central gummy smile and in the dynamic component of the upper part of the nasolabial fold.
- In Harmy
- Lies in the area of the Nasolabial Fold point, near the nose.
The levator labii superioris alaeque nasi is a thin, elongated muscle that runs down the side of the nose, from the root to the upper lip. It has two actions: it lifts the upper lip and flares the nostril. It is the most medial muscle of the lip elevator group and stands out in the expression of disgust, when the lip rises and the nostril wing opens.
Where is it and how is it built?
It arises from the upper part of the frontal process of the maxilla, beside the root of the nose, and runs down toward the lip, splitting into two slips:
| Slip | Insertion | Action |
|---|---|---|
| Medial | Greater alar cartilage and skin of the nostril wing | Flares the nostril and lifts the wing |
| Lateral | Upper lip, blending with the levator labii superioris and the orbicularis oris | Lifts and everts the upper lip |
It is a superficial muscle, covered only by skin and subcutaneous tissue for most of its course. The vein and the angular artery run near its border, along the side of the nose toward the inner corner of the eye. The exact course varies: the artery can pass over, under or between the fibers of the muscle.
Why does it matter in facial harmonization?
The muscle is relevant in three situations:
- Gummy smile: it is one of the elevators involved when the lip rises more than usual. Because it is the most medial, it has more influence on gum exposure at the front teeth. Management and non-muscular causes are in botulinum toxin for gummy smile.
- Nasolabial fold: its contraction deepens the upper part of the smile lines, near the nostril wing. Part of the fold is dynamic, and filling without considering the muscle action can give a result below expectations.
- Lines on the nasal dorsum: the wrinkles that appear when scrunching the nose are mainly associated with the transverse part of the nasalis muscle, but the levator of the wing contributes at the side, and the assessment usually looks at both.
How does it show up in the assessment?
- Ask the patient to smile broadly and observe gum exposure at the front teeth.
- Ask for the expression of disgust: nostril flaring and lip elevation show the strength of the muscle.
- Assess the upper part of the nasolabial fold at rest and in movement, to separate the static component from the dynamic one.
- Photograph from the front and smiling before any treatment, to record asymmetries.
Also called: levator labii superioris alaeque nasi, LLSAN, common lip and nostril wing elevator.
Frequently asked questions
What is the function of the levator labii superioris alaeque nasi?
It has two actions: it lifts the upper lip and flares the nostril. It is the muscle that contracts in the expression of disgust, when the lip rises and the nostril wing opens.
Is this muscle related to gummy smile?
Yes. Together with the levator labii superioris and the zygomaticus minor, it lifts the lip when smiling. When it is hyperactive, it contributes to exposing gum, especially around the front teeth.