The depressor septi nasi pulls the nasal base and septum downward during animation, producing the tip droop during smiling that some individuals find aesthetically objectionable. Its activity during smiling links the nasal tip position to the upper lip, and its release or denervation is a component of rhinoplasty procedures to prevent or correct a drooping nasal tip during animation.
| Origin | Incisive fossa of the maxilla above the central incisors |
|---|---|
| Insertion | Mobile portion of the nasal septum and the alar base |
| Nerve Supply | Buccal branch of the facial nerve (CN VII) |
| Blood Supply | Superior labial artery |
| Actions | Depresses the nasal septum and narrows the nasal base during contraction; Responsible for nasal tip depression during smiling in susceptible individuals |
|---|
By pulling the septum downward it widens the nasal base and narrows the nasal aperture, functions that are opposite to the nasalis alar part and contribute to the complex dynamic nasal airway control during expression.
Depressor septi nasi hyperactivity in some patients causes the nasal tip to drop significantly during smiling, which is an aesthetic concern addressed by releasing or weakening the muscle during rhinoplasty, or by Botulinum toxin injection into the muscle above the upper lip to temporarily reduce this movement.
The depressor septi nasi is not directly palpable but its function is assessed dynamically by observing nasal tip position change during smiling.
Excessive nasal tip depression during animation from hyperactive depressor septi nasi, addressed surgically during rhinoplasty by muscle release or conservatively with Botulinum toxin injection.
