Posterior Dilator Naris

Description

Framed on the lateral nose of an adult male, the posterior dilator naris is isolated along the alar cartilages, with its fibers blending into the alar part of the nasalis and adjacent nasal musculature. Surrounding facial muscles remain visible in subdued tone, allowing you to orient the red-highlighted slip relative to the orbicularis oculi superiorly and the levator labii superioris alaeque nasi running inferomedially toward the upper lip. The muscle lies superficial to the cartilaginous framework of the ala nasi and acts on the posterior aspect of the naris, widening the nostril by laterally drawing the alar margin. Attention to this small muscle pays off in both function and reconstruction. Altered nasal valve mechanics after rhinoplasty, alar base reduction, or cleft lip nasal repair often involve the balance between alar cartilage position and the perinasal musculature that exerts chronic resting tone. Subtle denervation or scarring in the nasalis and dilator naris region can contribute to dynamic nasal obstruction, and this view helps separate soft-tissue causes from purely cartilaginous collapse. Small, easy to miss. Clinicians teaching botulinum toxin planning around the upper lip and nose also benefit from clear depiction of the muscle’s relationship to levator labii superioris alaeque nasi and the alar part of nasalis, where diffusion can change nostril flare and upper lip elevation. Use this plate in head and neck anatomy courses, facial expression modules, or surgical texts discussing external nasal valve dynamics, rhinoplasty, or cleft nasal deformity. It also fits ENT and plastic surgery lectures where precise naming and fiber direction of the dilator naris support preoperative marking and postoperative assessment. Anatomical accuracy verified by SciePro's Medical Advisory Board.