The nasalis muscle is a sphincter-like muscle of the nose. It has a transverse part and an alar part. It compresses the nasal cartilages, and can "flare" the nostrils. It can be used to test the facial nerve (VII), which supplies it.

Structure

The nasalis muscle covers the nasal cartilages of the lower surface of the nose. It consists of two parts, transverse and alar:

Nerve supply

Like all the other muscles of facial expression, the nasalis muscle is supplied by the facial nerve (VII).

Function

The nasalis muscle compresses the nasal cartilages. It may also "flare" the nostrils.

Clinical significance

Cleft lip and cleft palate

The nasalis muscle is one of the key muscles not formed or inserted correctly with cleft lip and cleft palate deformity. The head of the transverse part needs to be identified during reconstructive surgery so that it can be surgically sutured (connected to) the nasal septum. The origin at the maxilla may also be repositioned for better symmetry.

Facial nerve testing

Due to it being superficial, the nasalis muscle can be used to test the facial nerve. Specifically, it can be used to test the zygomatic branches.

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