The nasalis muscle covers the
nasal cartilages of the lower surface of the
nose. It consists of two parts,
transverse and
alar: • The
transverse part (
compressor naris muscle) arises from the
maxilla, above and lateral to the
incisive fossa. Its fibers proceed upward and medially, expanding into a thin
aponeurosis which is continuous on the bridge of the nose with that of the muscle of the opposite side, and with the aponeurosis of the
procerus muscle. It compresses the nostrils and may completely close them. • The
alar part (
dilator naris muscle) arises from the
maxilla over the lateral incisor and inserts into the
greater alar cartilage. Its medial fibres tend to blend with the
depressor septi nasi muscle, and has been described as part of that muscle.
Nerve supply Like all the other muscles of facial expression, the nasalis muscle is supplied by the
facial nerve (VII). == Function ==