The nasolabial fold: an attempt at synthesis.

There is now enough information on the nasolabial fold to try to synthesize it with other well-known structures, such as the dermal terminations of the facial muscles, the superficial musculoaponeurotic system, and the fat pad. Rest dynamic equilibrium is a good concept to use to understand the nasolabial fold, because the nasolabial fold is not a passive, definitive structure, but an evolutive border whose limits depend on the absence or presence of fibromuscular terminations crossing the superficial musculoaponeurotic system of the cheek. A simple photograph of two men will help illustrate the difference between the convex and the concave nasolabial fold.