Depressor septi nasi muscle: anatomy and the nasal tip
- Muscle
Quick facts
- Origin
- Incisive fossa of the maxilla, above the roots of the central incisors, with fibers that blend with the orbicularis oris.
- Insertion
- Base of the medial crura of the alar cartilages and the mobile part of the nasal septum.
- Action
- Pulls the columella and nasal tip down and shortens the upper lip, especially when smiling and speaking.
- Innervation
- Buccal branch of the facial nerve.
- Relevance in facial harmonization
- Explains the nasal tip that drops when smiling and figures in toxin and nonsurgical rhinoplasty planning.
The depressor septi nasi is a small muscle of the face that runs from the maxilla, just above the central incisors, to the base of the columella. When it contracts, it pulls the tip of the nose down and shortens the upper lip. It is responsible for the nasal tip that "drops" when smiling, a common complaint among people seeking nonsurgical rhinoplasty or smile treatment.
Where is it and how is it built?
The muscle arises from the incisive fossa of the maxilla and rises, on each side of the midline, behind the upper lip. Some of its fibers blend with the orbicularis oris muscle, which explains its link to lip movement. It inserts at the base of the medial crura of the alar cartilages and into the mobile portion of the septum, that is, the columella.
The anatomy varies quite a bit. There are descriptions of muscles that insert only into the orbicularis, of muscles that reach the cartilages and of cases where it is poorly developed. Its innervation comes from the buccal branch of the facial nerve.
| Feature | What to observe |
|---|---|
| Position | Paramedian, at the base of the columella and in the upper lip |
| Associated movement | Tip drops and upper lip shortens when smiling |
| Neighboring muscles | Orbicularis oris, nasalis (alar part) |
| Nearby vessels | Branches of the superior labial artery, including the columellar artery |
Why does it matter in facial harmonization?
The depressor septi influences two profile measurements: the position of the nasal tip and the nasolabial angle. When it is strong, the angle closes more in the smile, the tip looks longer and a transverse fold may appear in the upper lip.
In practice, it shows up in three situations:
- Tip that drops when smiling: botulinum toxin in the muscle is described for reducing this movement.
- Nonsurgical rhinoplasty: a very active depressor can undo part of the tip projection gained during speech and smiling.
- Gummy smile: shortening of the upper lip adds to the effect of the lip elevators. The topic is covered in botulinum toxin for gummy smile.
How does it show up in the assessment?
- Profile at rest and smiling: compare the position of the tip and the nasolabial angle in the two photos.
- Palpating the columella while smiling: contraction of the muscle can be felt at the base of the nose.
- Fold in the upper lip: a transverse line below the columella during the smile suggests an active muscle.
- Upper lip length: a short lip makes the drop of the tip more noticeable.
The full anatomy of the region is in the nose area, and the overview of all muscles treated with toxin is in muscle map for botulinum toxin.
Also called: depressor septi nasi, nasal septum depressor muscle, nasal tip depressor.
Frequently asked questions
Why does the tip of the nose drop when a person smiles?
Usually because of contraction of the depressor septi nasi, which pulls the columella and tip down while the upper lip rises. The effect is more visible in people with a more developed muscle or a short upper lip.
Does botulinum toxin lift the tip of the nose?
Toxin in the depressor septi can reduce the drop of the tip during a smile, but it does not change the structure of the nose or the position of the tip at rest. The effect is temporary and depends on the assessment of the licensed professional.