The alar part of the nasalis (also known as alar nasalis, dilator naris, latin: pars alaris musculi nasalis) is a portion of the nasalis muscle that dilates the nostril.
The alar part of the nasalis originates from the outer surface of the maxilla above the region of the lateral incisor tooth.
The alar nasalis inserts into the skin along the posterior circumference of the lateral crura.
The alar nasalis lengthens the nose and dilates the nostrils.
The innervation of the alar nasalis is supplied by the buccal branch of the facial nerve (CN VII).