Chin is commonly known as chin, and chin retraction deformity is a common facial defect around us. What is mandibular retraction deformity and how to correct it? Aesthetic observation: from the front, the height of the upper and lower lips accounts for one third of the face, of which the upper lip is 1/3 and the lower lip is 2/3; When viewed from the side, draw a horizontal line between the tragus and the lower orbital margin, then draw a vertical line from the nasal root, extending down to the chin (nasal root vertical line), and draw the same vertical line in front of the lower orbital margin (lower orbital margin). It can be divided into normal (the chin is between two lines), protrusion deformity (the chin exceeds the vertical line of the nasal root) and retraction deformity (the chin retracts beyond the orbital line). Including mild: the posterior contraction distance is below the orbital line 1cm; Medium:1-2 cm; Severe: Retraction exceeds 2cm). For protrusion deformity, the bone to be removed should be measured according to ordinary X-ray film or 3DCT. Generally, the internal diameter of the mouth is used for osteotomy with a saw or chisel, and attention should be paid to prevent mental nerve from being damaged during the operation. Postoperative pressure dressing. Correction of chin retraction deformity: preoperative preparation: X-ray film to understand the retraction and occlusion relationship of teeth; According to the proportional relationship between nose, upper lip and chin, the thickness of chin should be measured, and the effect of chin augmentation can also be simulated by computer. Operation: 1, chin filling: suitable for patients with mild retraction deformity. Carved with medical solid silicone rubber or autogenous bone, implanted under the periosteum of mandible. 2. Osteotomy of the mental bone: if there is no wrong deformity, horizontal osteotomy of the mental bone can be used; If there is dislocation, the mandible splits longitudinally and the whole mandible moves forward. Precautions after operation: Generally, pressure dressing is needed after operation, antibiotics and da aubert solution are routinely used for gargling, and stitches are removed seven days after operation. The above is the way to correct chin retraction. I believe you have understood. I hope it helps you.