Porous high-density polyethylene (Medpor) is widely used as a filler material in clinical craniomaxillofacial cosmetic surgery because of its good biocompatibility and the ability of fibrous tissue vessels to grow in. In terms of biocompatibility, autologous materials such as fat, cartilage and fascia are incomparable to tissue substitutes, but autologous materials have the characteristics of complications in the donor area, easy absorption, not easily shaped and limited dosage. Medpor is a biologically porous material with an average pore diameter of 150um and a void volume of more than 50% of the entire material, and has the following advantages: good tissue biocompatibility; no rejection reaction, no absorption; because the tissue and blood vessels can grow into the material void after placement, its hardness, firmness and stability increase over time. It is non-toxic, can be shaped arbitrarily, and has sufficient strength and toughness. Therefore, Medpor is considered by many plastic surgeons to be the ideal biomaterial for craniomaxillofacial cosmetic surgery based on these advantages. In order to achieve the ideal treatment results, the indications should be strictly mastered before surgery, and it is best to use it when there is good tissue coverage and no infection in the tissue, and if necessary, dilators are feasible for pre-expansion of the skin to ensure good coverage of the prosthesis. Zhengzhou University First Affiliated Hospital Plastic Surgery Department Wang Ximei Level of filling: Due to the many causes of craniomaxillofacial defects, depressions and deformities, the extent of defects in different facial tissues is also wide, such as frontal, orbital and temporal cranial depression deformities caused by cranial trauma, zygomatic bone atrophy caused by hemifacial atrophy, facial soft tissue dysplasia, etc. According to different etiologies, different implant levels are selected in order to achieve better results. For cranial and orbital sunken deformities, Medpor should be placed into the superficial layer of the periosteum when it is placed for filling. For temporal sunken deformities, Medpor should be placed in the deep surface of the deep temporal fascia. In cases of zygomatic atrophy, Medpor should be placed on the surface of the zygomatic bone. In cases of mandibular hypoplasia, Medpor should be placed immediately on the surface of the mandible. For facial soft tissue defects, dermal fat flaps or fascial tissue flaps can be filled simultaneously or in two stages. Since Medpor is an inanimate material and cannot be extended for growth, it is not suitable for children in the growth phase to repair depressed deformities, and it is generally advisable to wait until after the age of 14!