The formation of Chuanzhi lines may be related to skin laxity, muscle contraction, tissue atrophy and other factors. 1. Skin laxity: with age, it will lead to excessive laxity and water loss of local skin, which may lead to the formation of Chuanzhi lines. 2. Muscle contraction: If you often make exaggerated expressions in your life, such as making faces and laughing, the local muscles will produce high-frequency contraction, which will lead to the formation of Chuan-Zi wrinkles. 3. Tissue atrophy: If the subcutaneous muscle tissue atrophies or breaks, it may lead to the lack of local skin support, resulting in the appearance of wrinkles. If you want to know the reasons for the formation of ChuanZi lines, it is recommended to go to a regular hospital to consult a doctor to clarify the cause of the disease.