Alar nasalis

The alar part of the nasalis (Latin: pars alaris musculi nasalis), also known as the alar nasalis or dilator naris posterior, is one of the nasalis muscle parts. It is classified as the nasal facial muscle. The alar nasalis is located in the wing of the nose, and it forms the nostril. This muscle dilates the nostril.

Origin

The alar part of the nasalis muscle originates from the frontal process of the maxilla above the region of the maxillary lateral incisor tooth.

Insertion

The alar nasalis inserts into the skin along the wing of the nose.

Action

The alar nasalis muscle lengthens the nose and dilates the nostril.

Innervation

The innervation of the alar nasalis muscle is provided by the buccal branch of the facial nerve (CN VII).

Blood supply

The alar nasalis receives arterial blood supply from the superior labial, lateral nasal and septal branches of the facial artery and the infraorbital branch of the maxillary artery.