Undeniably, a delicate and attractive small face is the favorite of modern women. However, with aging, facial fat, muscles and bones will gradually atrophy, especially the depression of the back cheeks (i.e. the outer area below the zygomatic bone), which gives a bad impression of aging, fatigue, and poor spirit. Moreover, with the common application of face slimming injection, individual candidates will find that the same problem as the above picture will occur after injection of face slimming injection, i.e., the depression of the back cheeks, which makes the originally young face appear old. Theoretically, since the effect of face slimming injection only lasts for about 6 to 12 months, the hollowing of the posterior cheeks caused by face slimming injection can be recovered. The typical recovery period for posterior cheek hollowing is 3 to 6 months. However, a recovery period of almost 6 months is also highly undesirable for candidates. Hyaluronic acid, as a temporary filler, takes 6-12 months to fully metabolize. Therefore, with hyaluronic acid fillers in the posterior cheeks, as the hyaluronic acid is absorbed and the bite muscle recovers, the posterior cheeks will remain full without becoming overly full.