There are many different types of allomaterials used for chin augmentation, such as silicone, expanded polytetrafluoroethylene and high-density polyethylene, to name a few. As early as the 1960s, bone resorption caused by allomaterials was reported. After decades of comparison, it is now generally accepted that relatively soft, small, well-fixed implants are more likely to cause resorption of the bone underneath the implant than harder, larger implants that are not well-fixed. Clinically, we often encounter more or less bone resorption when large silicone implants are removed from the chin. The reason for this may be that chin augmentation with larger implants causes excessive reverse tension in the soft tissues of the chin, and a greater force is exerted on the bone underneath the implant through the prosthesis. One of the characteristics of mandibular bone is that it resorbs under pressure and proliferates under tension, so under this constant pressure it causes resorption of the bone. At the same time the silicone prosthesis is harder, it is less cushioning relative to the soft prosthesis, so the pressure does not have any relief process, directly on the bone, is also a potential factor to cause bone resorption. At the same time, silicone or expanded PTFE prosthesis chin augmentation usually does not require additional fixation, they will produce micro-movement within the tissue, stimulate the surrounding fibrous tissue package to form a fibrous capsule to limit its activities, and this micro-movement is also a factor that causes bone resorption. Therefore, theoretically and through our clinical observations, we found that Medpor prostheses that are well fixed with titanium nails have less bone resorption. The reason for this may be that the titanium nail can firmly fix the material to the bone surface, the pressure of soft tissue will not further press the prosthesis to the bone surface, and there is no large force between the prosthesis and the bone surface, and at the same time, there is no micromovement of well-fixed prosthesis within the tissues, and the surrounding fibers and vascular tissues, etc., can grow into the prosthesis through the pores of the Medpor material, so that the prosthesis is better fixed in its original position. Of course, due to the Medpor chin augmentation in China application time is still short, need more cases to observe to determine the bone resorption. Most scholars believe that expanded polytetrafluoroethylene is less likely to cause bone resorption in the chin due to its softness and other characteristics, and although this seems to be true from clinical and literature reports, we still found one case in our statistics in which a more serious bone resorption occurred. Therefore, we believe that all allogenic materials cause some bone resorption, but the chance and degree of occurrence may be different due to the shape of the material. The analysis of the cases further suggests that bone resorption caused by chin augmentation with allogeneic materials is not only related to the shape of the material, but also has a variety of other complex causes. Another possible cause of resorption is surgical manipulation. In some cases, the surgeon has placed the prosthesis not in the thickest part of the bone cortex at the anterior inferior border of the chin, but rather in a part close to the alveolar bone, or the prosthesis has shifted upwards after the operation. This part of the bone is relatively loose and thin cortical bone and is therefore more susceptible to resorption under stress. Treatment of small chin deformities is divided into chin augmentation and chinoplasty. Mild and moderate chin deformities are more suitable for chin augmentation; while moderate and especially severe chin deformities are corrected by chin osteotomy and chinoplasty. Clinically, moderate or severe small chin deformity is often not a simple short chin deformity, often a small jaw or maxillary protrusion and other dental and maxillofacial deformities, individual cosmetic plastic surgeons do not have craniofacial surgery osteotomy plastic surgery technology or in order to cater to the patient’s requirements, for this type of patients are still applying allogeneic materials for chin augmentation, which can lead to serious bone resorption in the chin. The chin muscle is an important muscle in maintaining the shape of the lower lip and chin. It is the deepest of the lower lip muscle groups. It originates on the chin bone just below the lower incisors and the muscle fibers travel down and medially into the skin of the chin. Whether the patient has developmental hyperthyroidism of the chin muscle or due to severe micrognathia, vertical or horizontal anterior protrusion of the mandible or maxilla, there is overactivity of the chin muscle and overpowering of the chin muscle. In their resting position, eating, drinking, speaking, etc., the lower lip often tries to close the cleft, causing the chin muscles to contract with excessive activity, resulting in a constant increase in pressure or displacement of the prosthesis upward, which in turn causes bone resorption in the chin. Excessive activity of chin muscles is often manifested as pits of varying sizes in the skin of the chin, which suggests that this kind of patients are prone to bone resorption after chin augmentation or have already had bone resorption, and these patients need to be followed up regularly.Matarasso et al. reported a number of cases of severe bone resorption after chin augmentation with silicone gel prosthesis, and found the appealing pattern and characteristics through case analysis. regularity and characteristics. Also bone resorption seems to be reduced and self-limiting if the patient does not have significant hypertonicity of the chin muscles. This phenomenon can be confirmed in areas of very weak muscle strength, for example it is rare to see severe bone resorption in the corresponding areas after rhinoplasty or zygomatic augmentation with implants. Chin augmentation with allogeneic materials generally results in a greater or lesser degree of bone resorption, which usually occurs within 12 months after surgery. Because this type of bone resorption is self-limiting, most surgeons consider it acceptable and even clinically significant. This is because mild bone resorption does not cause significant cosmetic changes, and the resorptive groove formed in the chin area further stabilizes the prosthesis against later displacement. However, regular follow-up is required, and in severe cases of bone resorption, even to the point of eroding the roots or nerves, the prosthesis needs to be removed and the deformity corrected by osteotomy. This situation often occurs in severe small chin, small jaw after the application of allograft chin augmentation. These patients are often accompanied by excessive tension and hypermobility of the chin muscles. Therefore, in mild or moderate cases of simple small chin deformity, chin augmentation with an alloplastic material is a good choice. However, in the case of small chin or small jaw associated with malocclusion and hyperfunction of the chin muscles, chin augmentation with an alloplastic material is an option that should be considered, which requires jaw surgery using craniomaxillofacial surgical techniques. If an alloplastic material is used for chin augmentation, it should be followed up, and in case of severe bone resorption, it should be removed and corrected by osteotomy.