Musculovascular pattern in the myrtiform area: implications for cleft lip reconstruction

The myrtiform area plays a pivotal role in the functional/aesthetic dynamics of the face by accommodating multiple musculovascular structures. Nevertheless, it remains insufficiently documented in cleft lip reconstruction. This study investigated the morphological features of perioral musculovascular relationships in 21 adult and 3 fetal human specimens, and their surgical implications for cleft lip-nose repair. Three distinct muscles-nasalis, myrtiformis, and depressor septi nasi-constitute the myrtiform muscular system (MMS) and exhibit two patterns: W-type (69.2%) and V-type (30.8%). The nasalis and myrtiformis muscles attach to the lateral alar crus, with the former situated more laterally and attached to the outer alar surface. Neither the levator labii superioris alaeque nasi nor the orbicularis oris exhibits direct attachment to the lateral crus, and the superficial arterial course over these muscles limits their reliability as surgical landmarks for dissection at the alar base. Additionally, the vascular mapping shows four patterns (types A-D) with significant variations in supply to the alar region. Intraoperative observations reveal that, although muscle attachments resemble normal anatomy, cleft-related displacement results in distorted muscular vector orientations. The findings clarify the musculovascular morphology in conjunction with surgical procedures and demonstrate how a natural alar-facial groove can be restored in cleft lip-nose repair by detaching and repositioning the origin of the MMS. This approach rectifies the cleft-induced distortion of muscular vectors and preserves the anatomical insertion at the alar base, achieving realignment without extensive dissection.