Wrinkles are caused by the decrease of elastic fibers that maintain the normal tension of the skin, the weakening of sebaceous glands and the decrease of subcutaneous fat, which makes the skin and its deep tissues too loose and wrinkled.
Facial wrinkles are particularly common. With the growth of age, the body's metabolism weakens and aging wrinkles gradually form. Generally, the forehead appears first, followed by the crow's feet on the eyes and the smile on the cheeks.
In addition, because muscles often do the same reciprocating motion, the depressions between skin folds will leave traces. Extrusion wrinkles can be formed over time.