Orthognathic surgery has a long history of nearly 60 years, with Dingman and Harding first disconnecting the pterygomaxillary junction during the LeFort I osteotomy in 1951 and Obwegeser, the father of orthognathic surgery, first reporting the sagittal splitting of the mandibular ascending branch in 1957, both of which marked the beginning of orthognathic surgery’s evolution from a fumbling period to a mature The surgical approach. In those days, imaging was very rudimentary and only 2D projection films could be taken. Under these conditions, orthognathic surgeons established “an orthognathic surgical design process based on the four basic techniques of 2D projection films, facial arch transfer, facial shape prediction and model surgery”, which had to be considered an innovation. Although it was not precise and uncertain, it represented the highest level in that period of history. However, 60 years later, imaging and digital technologies have developed significantly, and these new technologies provide a more precise and visual means of orthognathic surgical design. At the same time, patients’ needs for surgery have also changed. The original purpose of orthognathic surgery was to change the relative position of the upper and lower jaws, re-establish the bite, and allow patients with congenital deformities to eat and speak normally. However, with the advancement of surgical technology and the improvement of people’s quality of life, patients’ concern for the postoperative facial shape has increased and the demand for surgery has gradually changed from “occlusionbased” to “appearancebased “appearance-based” model. The increased surgical requirements have put forward nearly demanding requirements for the preoperative design, which cannot be met by the traditional model surgical design process for the following reasons: 1. The error of the facial arch transfer may interfere with the doctor’s judgment of the degree of deformity; the deviation of the midline and jaw plane in some patients with low degree of deformity is between millimeters, and the error of the facial arch transfer may conceal the truth or even cause an illusion, resulting in the error of the surgical design. 2. Planar X-ray can only predict the anterior-posterior relationship of the jaws, but cannot be used in three dimensions for preoperative evaluation and surgical design; two-dimensional X-ray to see the anterior-posterior position of the jaws can be considered classic, but it cannot present the three-dimensional direction for the rotation of the occlusal plane and the asymmetry of the facial contour. Therefore, the surgical design can only meet the aesthetic requirements in the anterior-posterior direction, and the other directions can only be decided by the surgeon based on experience. 3, model surgery only see teeth, no bone, effect prediction by the doctor’s experience “brain”; traditional model surgery is the biggest drawback than the doctor can only see the movement of teeth, but can not see the shape of the bone. Especially nowadays, patients are increasingly seeking for the shape of apple muscle, nasolabial folds, nasolabial angles, and the “V-shaped” contour of the lower part of the face after surgery, while the traditional model surgery design only has teeth as a reference, and the cold plaster base cannot reflect the future contour of the face, so the surgeon cannot speculate on the details of the surgery. With the development of modern imaging and digital medical technology, especially in recent years, CAD/CAM technology has gradually entered the field of oral medicine, and 3D surgical planning based on 3D CT data has gradually replaced traditional model surgery and 2D projection measurement as the mainstream technology for orthognathic surgical design worldwide.