(I) Postural wrinkles:
These mainly appear on the neck. Multiple transverse wrinkles can be seen on the neck of a normal person from birth. These wrinkles do not necessarily indicate aging, but as a person ages and the platysma muscle contracts over the long term, these transverse wrinkles can deepen. The skin between the transverse wrinkles becomes loose, becoming a symbol of facial aging.
(II) Dynamic wrinkles:
This type of wrinkle is the result of the contraction of the facial expression muscles. Once they appear, they will not disappear even if the facial muscles are not active. Their location, time of appearance, and quantity vary depending on individual facial expressions and habits.
1) Forehead wrinkles: They appear in the middle of the forehead, running horizontally, which is the result of the contraction of the frontalis muscle. This type of wrinkle tends to appear earlier, with some people beginning to see these wrinkles during their youth.
2) Frown lines: They appear vertically between the eyebrows, which is the result of the contraction of the corrugator supercilii muscle located between the eyebrows.