Nasalis Under The Skin

Description

Shown in lateral profile on an adult male face, the nasalis muscle is presented deep to the skin of the nasal sidewall, with the transverse (compressor naris) fibers coursing superomedially across the dorsum toward the contralateral aponeurosis and the alar (dilator naris) fibers running inferolaterally toward the alar cartilage. Superiorly, the muscle blends with the procerus region near the nasal bridge, while anterior and inferior fibers relate closely to the lateral crus of the alar cartilage and the soft tissue of the external naris. Posteriorly, the nasalis abuts the maxillary facial surface and sits medial to the nasolabial soft tissues and anterior cheek musculature. Functionally, separating compressor from dilator portions matters because they have opposing effects on nasal airflow at the nasal valve and nostril rim. This is the anatomy behind dynamic nasal obstruction, where alar collapse during inspiration can occur after rhinoplasty, trauma, or facial nerve dysfunction, and where targeted modulation of nasalis activity can change tip support and flare. Small muscle, big consequences. Use this lateral, under-skin rendering for teaching facial expression musculature in head and neck anatomy, for illustrating the biomechanics of external nasal valve collapse in otolaryngology and facial plastic surgery texts, or for patient-facing surgical counseling diagrams that explain why nostril narrowing or flaring can follow cosmetic or reconstructive procedures. It also supports discussions of botulinum toxin injection planning in the perinasal region, where precise fiber direction helps avoid unwanted changes in upper lip and alar contour. Anatomical accuracy verified by SciePro's Medical Advisory Board.