Muscles of the nose
The description of the muscles of the nose and explanation of their functions is one of the most confusing aspects of the body of knowledge germane to rhinoplasty (Figure 1). In fact, many of the articles written about the nasal musculature assign different names and functions to the same muscles of the nose.2–5 All of these muscles are innervated by the VII cranial nerve. Following are the nasal muscles and an outline of their function:Figure 1
The muscles of the nose.
The most cephalic muscle of the nose is the procerus, which arises from the glabellar area, extends caudally in a vertical fashion, and joins with the wing-shaped nasalis transverse muscle covering the caudal portion of the nasal bones. The main function of the procerus is to move the eyebrows caudally; it can create wrinkles over the cephalic portion of the nose in aging patients. Ostensibly, removal of this muscle may elongate the nose.
The nasalis muscle has 2 components: (1) the transverse nasalis m. or compressor nasiand (2) the pars alaris (alar nasalis). The transverse part of the muscle spans the dorsum of the nose, covering the upper lateral cartilages. This muscle, also called pars transversa or compressor nasi, arises from the lateral cephalic portion of the subpiriform crescent. The pars transversa joins with the procerus muscle and the opposite muscle in the midline to form the nasalis-procerus aponeurosis. The pars transversa compresses and elongates the nose, contracts the nostrils, and narrows the vestibules. Although removal of the pars transversa may shorten the nose, it is inadvisable since removal may cause skin dimpling. Removal of the pars transversa muscle may also expose any imperfections in the frame because it eliminates the blanket effect that this muscle lends the nose.
The second component of the nasalis muscle, the pars alaris (alar nasalis) arises from the crescent origin of the maxilla and is more lateral and slightly caudal to the bony origin of the depressor septi nasi muscles. The alar portion partially covers the lateral crus of the lower lateral cartilages and assists in dilatation of the nares. Damage to this muscle may produce collapse of the external nasal valve. In ethnic noses, the pars alaris is much more developed and has a more important function.