Mandibular angle plastic surgery is a very important operation in facial modification. Methods Mandibular angle incision (that is, arc osteotomy or long curve osteotomy) and external plate splitting (or grinding external plate) were used. Some beauty seekers ask: will mandibular angle surgery (splitting or grinding the outer plate) proliferate? The answer is yes, there is the problem of hyperosteogeny, mainly because the human body itself has a repair mechanism. When the mandibular angle is removed or the outer plate is chopped (ground), new bone will be formed on the wound surface. After the mandibular angle is removed, the upper part of the mandible can appear spherical hyperplasia, but the appearance is generally not obvious. Another proliferation is that the bone marrow is definitely exposed after splitting the outer plate or grinding the bone. Within three months, the bone structure will be reconstructed, and the surface of the bone marrow cavity that was originally exposed will be reconstructed into bone cortex, covering the bone marrow. Or the exposed cancellous bone and bone marrow are directly transformed into cortical bone. After 3-6 months, the reconstruction is over. Usually, after grinding the outer plate, the bone will proliferate to a certain extent. After splitting the outer plate, the degree of proliferation will be smaller than that of grinding the outer plate. Another reason is that after bone grinding during operation, bone chips are not cleaned and exist in the wound surface, forming a scaffold for hyperosteogeny, which is easy to cause hyperplasia, so it is very important to wash them fully during operation.