(I) Postural Wrinkles:
These mainly appear on the neck. A normal person is born with multiple horizontal wrinkles visible on their neck. These wrinkles do not necessarily indicate aging, but as a person ages and the platysma muscle contracts over time, these horizontal lines can deepen. The skin between the horizontal wrinkles may become loose, becoming a symbol of facial aging.
(II) Dynamic Wrinkles:
This type of wrinkle results from the contraction of facial expression muscles. Once they appear, they won't disappear even when the expression muscles are inactive. Their location, timing, and quantity vary depending on individual facial expressions, movements, and habits.
1) Forehead Wrinkles: Appear in the middle of the forehead, running horizontally. They result from the contraction of the frontalis muscle. These wrinkles tend to appear earlier, with some people beginning to see them during their youth.
2) Glabellar Lines: Appear vertically between the eyebrows, resulting from the contraction of the corrugator supercilii muscle located between the eyebrows.
3) Eyelid Wrinkles: Appear on the upper and lower eyelids, often in large numbers. The upper eyelid wrinkles are finer, while the lower eyelid wrinkles are coarser. Their direction is generally vertical or slightly slanted. There might also be tear trough circles under the eyes. These wrinkles result from the contraction of the orbicularis oculi muscle.
4) Crow's Feet: Located around the outer corners of the eyes, arranged radially. Their length and number vary from person to person. These wrinkles result from the contraction of the orbicularis oculi muscle.
5) Nasolabial Fold Wrinkles: Appear on the cheeks, resulting from the contraction of the levator labii superioris muscle and the zygomaticus major muscle.
6) Cheek Wrinkles: Appear on the cheeks, resulting from the contraction of the levator labii superioris muscle and the zygomaticus major muscle.
7) Lip Wrinkles: Appear on the surface of the upper and lower lips, often in large numbers. The wrinkles on the upper and lower lips run vertically, while those at the corners of the mouth are arranged radially. These wrinkles result from the contraction of the orbicularis oris muscle.