The Morphological Structure of the Nasalis Muscle of a Male

Description

Across the external nose, the nasalis muscle is presented as two functionally distinct parts, the transverse part (compressor naris) sweeping medially over the nasal dorsum and the alar part (dilator naris) coursing inferiorly toward the alar cartilage at the margin of the nostril. Laterally, fibers arise from the maxilla near the canine fossa and run superficial to the nasal cartilages, blending with adjacent facial muscles at the nasofacial groove. Medial fibers approach the midline aponeurosis over the nasal bridge, while the alar slips track more inferiorly and laterally into the skin of the ala. Small muscle. Big effect. Understanding this arrangement matters when you are teaching how nasal aperture shape changes during speech and sniffing, and why the same patient can show alar collapse on inspiration after rhinoplasty or trauma. The alar part can be undermined or scarred during open or endonasal approaches, and loss of its tone contributes to external nasal valve compromise, a frequent cause of postoperative obstruction despite an otherwise straight septum. Botulinum toxin planning also benefits from clear localization, since injection into the transverse part can soften “bunny lines” while sparing unwanted effects on nostril flare. Facial anatomy courses, otolaryngology and plastic surgery texts, and preoperative counseling materials for functional rhinoplasty commonly need a clean depiction of the nasalis, including the relationship of its alar and transverse components to the nasal cartilages and overlying skin. It also fits well in modules on muscles of facial expression, with emphasis on subtle muscular control of the nostrils in a male adult specimen. Anatomical accuracy verified by SciePro's Medical Advisory Board.