The soft triangle revisited.

Five cadaveric adult human noses were examined to further elucidate the region of the soft triangle of the nose. Three distinct zones were found. Zone 1, just caudad to the lower lateral cartilages, consists of the fibers of the dilator nares anterior as it inserts into the dermis. Zone 2 is the dermal layer. Zone 3 is at the nostril rim and consists of muscle fibers interdigitating within the dermis; laterally, these fibers are continuations of the nasalis muscle, whereas medially they are extensions of the depressor septii muscle. Perpendicular incisions through any of these zones may cause notching and tip deformity. Incisions in zone 1 may, in addition, alter external nasal valve function by interrupting the fibers of the dilator naris anterior.