In wrinkle formation, a broad distinction can be made between dynamic wrinkles (caused by muscles) and gravitational wrinkles (caused by gravitation). Typical dynamic wrinkles are “glabella wrinkles”, “lofty brow” and “crow’s feet”. Examples of gravitational wrinkles are the “nasolabial fold” and “chubby cheeks”. A negative volume will arise primarily due to reduced elasticity combined with gravity, such as “deep under-eye circles” or “sunken cheeks”.
The following methods can be applied for these reasons: