Facial wrinkle reduction was initially a surgical procedure to lift an aging, sagging face by removing the skin at the edge of a facial flap and suturing the incision under some tension. Even the safest surgery is not guaranteed to be safe, and some complications may occur, such as: nerve damage, baldness… Why do these complications occur? First, nerve injury The common risk factors for facial nerve injury are: 1, temporary paralysis caused by the abnormal blocking effect of local anesthetics on a nerve branch, which can be fully recovered in a few hours; 2, the small branches near the expression muscles away from the section; 3, a nerve branch (trunk) away from the section caused by permanent facial nerve paralysis; 4, postoperative hematoma compression or over-tightening of the bandage can also cause reversible or irreversible nerve injury. Sensory nerve damage manifested as sensory abnormalities in the corresponding areas, most of which can be compensated or restored. Baldness: The hair follicles are damaged when the scalp flap is peeled too thin, or the hair follicles are damaged when applying the electric knife, which can lead to baldness. Scalp suture tension is too large, incision scar formation can lead to follicular degeneration. Attention should be paid to the direction of the incision to minimize follicular damage. Peel to master the correct plane and retain a certain amount of subcutaneous fat volume. To give a simple example (below): (Cross section of an incision in the sideburns and temporal region) 1. If the skin incision is parallel to the hair shaft, the scar will always remain in front of the hairline. 2. In the MACS procedure, the surgical incision is made in an oblique direction to the skin plane within the hairline. The scalpel is placed obliquely and the hair shaft is severed so that the hair follicles are preserved. Six to eight weeks after surgery, the hairs underneath will grow through the scar tissue and hide the scar well.