I. Clinical characteristics of aging Facial aging is the main manifestation of human aging, mainly manifested as facial wrinkles, the formation of upper and lower lid pouches, especially lower lid pouches; the deepening of nasolabial folds, and the formation of double jaws. Usually, the facial folds and wrinkles can be divided into: upright folds, power folds, gravity folds and comprehensive folds. 1, upright crease lines It is some natural crease lines that may already exist at birth, only to become more obvious with age, after the disappearance of its early childhood membrane lipids. These crease lines do not really reflect the aging process, and are only emphasized as an important technical sign of plastic surgery, they are formed due to excessive skin, or due to the bending and stretching of certain areas, usually They are easily found on the posterior and anterolateral sides of the face and neck, arranged horizontally or intersecting horizontally, with a number of 1-3 lines. 2, power crease line is due to the repeated pulling of the skin during the activity of facial expression muscles. Its generation time and quantity vary greatly from person to person, usually in adolescence due to the activity of frontal muscles began to produce power wrinkles in the forehead (i.e. the appearance of frontal lines), the position, quantity, depth and continuity of frontal lines are different, basically horizontal, from the front edge of the temporal fossa across the forehead extended to the opposite side, once formed, it will become extremely obvious in the resting state. The second is the wrinkles that appear after the age of 20 due to the contraction of the orbicularis oculi muscle – the crow’s feet, usually at the outer canthus of the eye, called “claw lines” or “laugh lines”, whose position, number and depth are variable. The location, number, and depth of these wrinkles are variable, with a radial, fan-shaped distribution at the outer canthus and a gradual progression toward the lower part of the eye, extending from the lateral aspect of the lower lid toward the zygomatic arch. The nasolabial folds, which are both gravitational and dynamic in nature, are very important in cosmetic surgery, as they are in the area where the skin of the lips is closely connected to the orbicularis oris muscle below it, and the cheek skin is loosely connected to the cheek fat pad. The appearance of the nasolabial folds is mainly due to the pulling of the suborbital and frontal fibers of the muscle above the lips and the fibers of the zygomaticus muscle. The nasolabial communication often starts from the nasal cartilage and extends downward, its length and depth varies from person to person, usually ending at 1cm from the corner of the mouth, and can also extend downward to the lower jaw, participating in the formation of the “jaw”. The vertical wrinkles are caused by the activity of the frown muscle. The number, depth, length and regularity of the wrinkles vary from person to person. They originate from the middle lower part of the frown muscle, travel along the side of the nose on both sides of the nasal pole and become curved, and become straight when they cross between the eyebrows and go upwards, terminating in the middle lower part of the forehead, where one or more vertical wrinkles are often formed in the central area, sometimes extending to the edge of the hairline of the forehead. The horizontal wrinkles at the nasal root are relatively not introduced to the note day, usually short transverse wrinkles, irregular in depth and number, can be 1-3, mainly due to the activity of Procerus Muscle. Horizontal wrinkles may sometimes appear at the inferior border of the nasal columella, mainly due to the septal compression muscle. Around the age of 50, wrinkles around the perioral area also appear, first on the upper lip and then gradually on the lower lip, due to the contractive pull of the orbicularis oris muscle. They are vertical in shape, and their number, depth and length vary irregularly. Due to the activity of the cheek muscles, irregular “dimple-like wrinkles” are also produced in the plane of the cheek, which is not common to everyone, but may become extremely prominent in some people. 3, gravitational wrinkles Gravitational wrinkles are formed unconsciously, and their time of occurrence is also very variable, usually becoming more obvious at the age of 40 or later, and develop in correspondence with gravity. As a result of changes in the skin and subcutaneous tissue, accompanied by the formation of dynamic folds, as well as the atrophy of the facial skeletal structure and the loss of teeth and alveolar protrusions, sagging, unpadded skin is formed under the influence of gravity, at which point gravitational wrinkles become very pronounced throughout the face and neck and seem to originate in their underlying bony prominence (periorbital rim, cheekbones and mandible). The skin of the upper eyelid becomes horizontally redundant and tends to dry out forming a loose crease over the eyelashes, especially in the outer one-half of the eyelid, and then gradually drops down to the lower part of the supraorbital rim and forms a redundant upper face skin. Similar changes occur in the lower eyelid. Both upper and lower eyelids are affected by bulging orbital septum fat and form lid bags. As we age, the septal fat may shrink, causing the eye to look more sunken. As the subcutaneous fat gradually disappears, especially in the cheek fat pads, the cheeks become sunken and the skin from the zygomatic arch to the jaw hangs in a vertical line forming the “jowls” feature. As a result of overall atrophy, secondary wrinkles are formed on the entire face and neck, more pronounced on the cheeks, lips, forehead, preauricular region, anterior region of the neck behind the neck, and later, gradually involving the nose and earlobes, secondary furrows parallel to the nasolabial folds, originating at the corners of the mouth and going downward toward the outer part of the forehead, which depend to some extent on the pulling of the perioral compression muscles, but more The formation of these wrinkles depends to some extent on the pulling of the perioral compression muscles, but mainly on the effect of gravity. The neck also shows a corresponding variety of variations, with the effect of gravity more prominent on the horizontal upright folds, which form vertical folds under the chin. At rest, the horizontal upright folds become more severely prominent and persistent, creating secondary interlocking wrinkles in the posterior neck area. When there is no fat pad under the chin to fill the intertwined space, two long straight “turkey-like” wrinkles form in the neck, starting from the sides of the lower jaw margin, often overlapped by the jaw, and ending at the sternal head of the sternocleidomastoid muscle. There may be plausible alterations in the subchin area (in different bodies), and in some individuals with a familial tendency to develop excess subchin fat, which is not necessarily associated with obesity. Gonzalez-Ulloa and Flores reported in 1965 on the changes in facial appearance that occur during aging, highlighting the atrophy of adipose tissue that diminishes the support of eyelid tissue and leads to bulging of orbital septal fat within the eyelid. Gonzalez-Ulloa, Simonin and Flores (1971) applied cranial radiographs to assess changes related to aging of the face and neck, and they mapped gravitational changes in the brow, corners of the mouth and neck tissues, with dramatic changes in the brow usually occurring between 24 and 40 years of age. The most pronounced period of nasolabial folds decline occurs after the age of 50, and the most prominent sagging of neck tissues occurs between the ages of 25 and 55 (the angle between the neck and the facial plane). 4.Comprehensive wrinkle line It is a combination of the above wrinkle lines. Second, the clinical typology of facial aging can usually be divided into four types. （This type is characterized by skin laxity of the entire face and neck, and only mild skin laxity in the nasolabial folds, mild skin laxity in the submandibular line or jaw, and skin laxity in the neck. However, the texture of the skin is relatively good and there are no signs of striae of the cervical muscle in the neck. (ii) Type II This type of skin laxity is basically similar to or more lax than the first type; however, the skin laxity at the submandibular line or jaw is more pronounced than above, and a more pronounced double jaw is present. The anterior cervical region does not show a more obvious striated phenomenon of the broad cervical muscle. (iii) Type III This type is characterized by the characteristics of the two above-mentioned types and the presence of more pronounced striated symptoms of the broad cervical muscle. The treatment of the striated broad cervical muscle is as follows: 1.No treatment (for those with less obvious symptoms); 2.Treatment of the marginal part only; 3.Treatment of the anterior or posterior part of the striated broad cervical muscle or both the anterior and posterior sides; 4.Complete separation of the broad cervical muscle; 5.Overlapping suture treatment of the broad cervical muscle backward; 6.Separation, cutting and suturing of the broad cervical muscle. 6. Separate, cut and suture the latissimus dorsi muscle. The above methods should be chosen according to the patient’s condition. (iv) Type IV This type has all the characteristics of the above, and it has an extremely obvious feature that the lower part of the chin or the neck has significant fat.