Anterior Dilator Naris Muscle Under the Skin, Anterior View

Description

Beneath the facial skin in anterior view, the anterior dilator naris appears as fine muscular slips at the inferolateral margin of the external nose, blending with the alar part of the nasalis and inserting into the lateral crus and skin of the ala nasi. Medial to these fibers lies the nasal vestibule and nostril rim, while superiorly the muscle relates to the lower nasal sidewall and the cartilaginous framework of the nose (alar cartilage highlighted in blue). Lateral facial muscles provide context, with orbicularis oculi encircling the palpebral fissure, levator labii superioris descending toward the upper lip, and orbicularis oris forming the sphincter around the oral fissure. Bilateral symmetry makes side-to-side comparison straightforward. Small as it is, this muscle matters when you teach or treat nasal valve mechanics. Contraction of the dilator naris contributes to widening the nostril aperture and supporting the external nasal valve during inspiration, a concept that becomes concrete when discussing nasal obstruction from alar collapse, post-rhinoplasty weakness, or facial nerve dysfunction affecting perinasal tone. This frontal subcutaneous perspective also helps clarify how perinasal injection planes for local anesthesia or cosmetic neuromodulators can inadvertently alter nostril shape or upper-lip dynamics by diffusion into adjacent nasalis and levator labii superioris fibers. A deceptively compact region. Use this artwork to illustrate facial expression and nasal airway anatomy in gross anatomy, head and neck modules, or ENT teaching sessions that pair surface form with the underlying mimic muscles. It also suits surgical texts and patient-facing rhinoplasty or nasal valve repair materials where accurate relationships between alar cartilage, nasalis, and surrounding muscles are non-negotiable. Anatomical accuracy verified by SciePro's Medical Advisory Board.