Nasalis muscle: transverse and alar parts and nose wrinkles
- Muscle
- Highlighted area
Quick facts
- Location
- Over the side and dorsum of the nose, from the maxilla to the alar cartilage and the dorsal aponeurosis.
- Parts
- Transverse (nostril compressor) and alar (nostril dilator).
- Action
- The transverse part compresses the nostril and wrinkles the dorsal skin; the alar part opens the nostril.
- Innervation
- Branches of the facial nerve, usually described as buccal, with variable contribution from the zygomatic branch.
- Relevance in HOF
- The transverse part is mainly responsible for bunny lines on the nose, which are treated with toxin.
The nasalis is the muscle that covers the side and dorsum of the nose and controls how wide the nostrils open. It has two parts: the transverse part, which compresses the nostril and wrinkles the dorsal skin, and the alar part, which opens the nostril. In HOF it is the muscle behind bunny lines, the oblique lines that appear on the side of the dorsum when smiling or scrunching the nose.
Where is it and how is it built?
Both parts arise from the maxilla, near the nasal opening, above the front teeth, and follow different paths:
| Part | Origin | Insertion | Action |
|---|---|---|---|
| Transverse | Maxilla, lateral to the nasal opening, near the canine | Aponeurosis over the dorsum, continuous with the opposite side and with the procerus | Compresses the nostril and folds the dorsal skin |
| Alar | Maxilla, above the lateral incisor | Alar cartilage and skin of the nasal ala | Opens the nostril and pulls the ala down and outward |
The transverse part forms, together with the opposite side, a thin sheet over the dorsum. Innervation comes from the facial nerve, usually through buccal branches. In the same area run branches of the dorsal nasal artery and the lateral nasal artery, which communicate with the ophthalmic artery system.
Why does it matter in HOF?
- Nose wrinkles: contraction of the transverse part, together with the medial fibers of the levator labii superioris alaeque nasi, forms the oblique lines on the side of the dorsum. They are dynamic wrinkles and a described indication for botulinum toxin.
- Compensation after toxin: after glabella treatment, bunny lines may become more noticeable, because the nose starts to take over the scrunching.
- Breathing and nostrils: the alar part helps keep the nostril open on deep inspiration; it is worth noting whether the patient flares the nostrils markedly.
Managing these lines is covered in botulinum toxin for nasal lines.
How does it show up in the assessment?
- Wide smile and nose scrunch: show the extent and symmetry of the bunny lines.
- At rest: separates lines that appear only in motion from those already visible.
- Glabella treated before: ask about recent toxin in the glabella, which may be accentuating the lines.
- Nostrils on inspiration: observe the flaring, linked to the alar part.
The tip of the nose has its own muscle, the depressor septi nasi. The full anatomy is in the nose area.
Also called: musculus nasalis, compressor and dilator muscle of the nostril, bunny lines muscle.
Frequently asked questions
Which muscle forms the wrinkles on the nose when smiling?
Mainly the transverse part of the nasalis, helped by the medial fibers of the levator labii superioris alaeque nasi and the procerus. The oblique lines on the side of the dorsum appear when smiling or scrunching the nose.
Can bunny lines appear after toxin in the glabella?
They can become more evident. With the glabella and crow's feet treated, the nasalis sometimes starts to compensate for the movement. That is why assessing the nose in motion is part of planning the area.