I. Causes and Purposes of Cranial Repair Cranial repair is a common brain surgery procedure to repair the skull in response to traumatic brain injury resulting in cranial defects. Reasons for cranial bone repair: craniocerebral trauma and brain surgery (mainly acute-phase aneurysm, cerebral hemorrhage, etc.) to remove the bone flap. Due to the change in shape of the cranial defect area, the scalp is subjected to atmospheric pressure, which causes it to sink in and compress the brain tissue. Often the bone window is fuller in the morning and more depressed after walking or at night. Patients with cranial defects often have a heavy burden of thought such as insecurity, and can cause headaches, dizziness, fear of vibration and other syndromes. The longer the cranial defect, the higher the incidence of cranial defect syndrome and secondary brain damage. In order to restore the airtightness of the cranial cavity, maintain physiologic intracranial pressure stability and alleviate cranial defect syndrome. Cranial bone repair should be performed in all cases where the diameter of the cranial defect is more than 3 centimeters, there is no muscle coverage, and there are no contraindications. Addressing the absence of effective protection of brain tissue, impaired blood supply, and abnormal cerebrospinal fluid circulation in the defect area also requires addressing the issue of shape repair and plasticity. The timing of surgery is generally considered appropriate to repair 3~6 months after craniotomy, the defect site pressure is not high, no infection, ulcers and other factors that are not conducive to the healing of the incision. Common cranial repair methods and materials 1, titanium plate: for more flat small defects, two-dimensional titanium plate fixation can be used. For larger defects involving frontotemporal area, three-dimensional plasticized titanium plate is a better choice. At present, my department are using three-dimensional plastic titanium mesh, the patient only needs to receive a CT examination, complete the three-dimensional reconstruction of CT data, and then the digital design of the restoration on the computer to complete the simulation of the assembly, the design of the data using digital molding technology to create a model of the restoration, and then use digital manufacturing technology to produce titanium restorations, compared to the model of titanium alloy can be obtained after the shear edge of the restoration. 2, plexiglass or silicone plate: plexiglass or silicone plate is irritating, will age over time, hardness is insufficient, due to local collision caused by the rupture of the plexiglass sheet; produce subcutaneous effusion, and there is the possibility of infection to failure, sometimes infected in the postoperative period after a long time to produce, has been rarely used. 3, autologous cranial flap: any reason for craniotomy, in the cut cranial flap, can not be immediately replanted in situ, can be buried through the autologous subcutaneous preservation of retention. Need to operate in the abdomen, leaving scars, although the autologous cranial group of fewer complications, the repair of the appearance of satisfaction, but need to operate again and increase the patient’s pain, and the existence of cranial bone resorption becomes small or even necrosis, and after the repair of the shortcomings of the loosening of the fixation is not stable. Third, the best time for cranial repair, in principle, try to repair early, restore the integrity of the cranial cavity, conducive to the recovery of the condition. For craniocerebral injury or aneurysm and other surgical causes of cranial defects, as long as the patient is clear, head invagination is obvious, and the local skin is not infected, we advocate that the repair within 1-3 months. If there is an open injury or local infection in the early stage, it needs to be repaired 6 months-1 year after infection control, aiming at p less infection. IV.PRE-OPERATIVE PREPARATION FOR CRANIAL REPAIR All patients had no contraindications to surgery, and all underwent cranial CT and frontal bone X-ray radiography. The digital forming group routinely performs thin-layer CT scanning with a layer thickness of 2mm, and carries out three-dimensional reconstruction of the frontal bone, and then uses the “titanium mesh digital forming machine” to form and process the titanium mesh, to create a personalized titanium mesh restoration that is completely consistent with the patient’s frontal bone defects, and then sterilizes it for spare parts; the time required is about 3 working days. V. Surgical method of cranial bone repair All patients were put under general anesthesia with tracheal intubation, and the covering method was used for repair. Fixed with matching self-tapping titanium nails; routine application of antibiotics to prevent infection, 1-2 days to remove the drainage tube, 10-12 days to remove the stitches.