The Posterior Dilator Naris Muscle of a Male Viewed Laterally

Description

Arising from the maxilla near the canine fossa region and running superiorly into the alar cartilage, the posterior dilator naris (dilator naris posterior) is presented in lateral view along the external nose of an adult male. Fine muscular fibers track deep to the skin of the nasal ala, positioned anterior to the nasalis and adjacent to the lateral nasal cartilage, with their insertion approaching the posterior aspect of the alar rim. Medially, the muscle blends with other perinasal mimetic fibers around the nostril margin; laterally it tapers toward the soft tissue of the nasal sidewall. Small structure. Easy to miss. Functional anatomy of the dilator naris matters when you are teaching nasal valve mechanics or planning aesthetic and reconstructive work around the alar base. Weakness, scarring, or denervation in the perinasal muscles can contribute to dynamic external nasal valve collapse, and this slip helps explain why some patients flare the nostrils during exertion while others cannot. For surgeons, the muscle’s proximity to common alar base incisions and to the facial artery and vein region makes it a practical landmark when discussing soft-tissue handling, postoperative distortion, and subtle asymmetries in nasal animation. Use this artwork for head and neck anatomy modules on muscles of facial expression, rhinoplasty and alar base reduction teaching files, or clinical publications on nasal obstruction and nasal valve repair techniques. It also supports patient-facing education on nasal flare and postoperative changes in nostril shape when you need a clear lateral relationship between muscle fibers and alar cartilage. Anatomical accuracy verified by SciePro's Medical Advisory Board.