The marionette lines, also known as the labiomandibular groove, extend from the corners of the mouth outward and downward to the anterior groove of the jaw, and are a manifestation of facial aging that causes the corners of the mouth to sag. As facial aging increases, the marionette lines gradually deepen, making the sagging of the soft tissues of the jaw skin more pronounced. Volume loss in the area of the marionette lines is often accompanied by volume loss in the area above the external chin, so it is important to fill not only the skin wrinkles in this area, but also to fill moderately the transition area in front of it to reconstruct a smooth transition contour between the chin and the side of the jaw. Cosmetic injections with hyaluronic acid are a very safe “minimally invasive cosmetic anti-aging” procedure, and patient satisfaction is generally very high. Adverse reactions are usually caused by transient allergic or local tissue damage. During lip fillers, the herpes simplex virus may be activated to reactivate. Most adverse reactions are transient allergic reactions and redness of the injection site. Long-term adverse reactions, mainly consisting of persistent foreign body-related inflammatory reactions, are much rarer. Bruising is the most common complication. Preventive measures include discontinuation of anticoagulants (when condition permits), aspirin, vitamin E, fish oil, etc. and preoperative icing. Management measures include: ice, compression, bruise-reducing creams or herbal remedies. A common adverse reaction to hyaluronic acid is a blue-gray discoloration due to overly superficial injections, known as Tyndall’s phenomenon, which is formed by scattering of different wavelengths of light within the colloid. Adverse reactions to hyaluronic acid are rare, and many can be resolved with hyaluronidase. Hyaluronidase can break the glucosamine bond between C1 of glucosamine and C4 of glucuronide, thus degrading hyaluronic acid with remarkable effect.