Generally, patients with cranial defects should go to the hospital to have a CT scan of the brain, and then when the film comes out, you can compare the film to the lighted area. If it is a cranial defect, there will be some black areas on the cranial contrast of the patient, and these black areas are usually the parts of the cranial defect. In general, cranial defects are caused by open cranial injury or firearm penetration injury, and some patients have residual bone defects due to surgical decompression or craniectomy. Of course, if the skull defect is more than three centimeters in diameter, especially if it is located in the frontal area, affecting the aesthetics and safety of the defect, there are often symptoms of one kind or another, such as dizziness, headache, local pain, irritability manifestations, or some patients may have a fear of pulsation, expansion, collapse of the defect area. Therefore, there is a fear of sunlight, fear of vibration, and even fear of loud noises. Therefore, it is recommended that patients with skull defects should have their skull repaired promptly. Currently we use the very advanced PEEK material. It is able to completely restore the anatomical structure of the skull. In addition, this PEEK material is bionic bone, which can be highly compatible with the autologous skull and has comparable properties to the autologous skull in terms of elasticity, heat transfer, hardness, and stability, especially for pediatric patients, and can better adapt to the growth and development of the autologous skull. the main advantage of PEEK is that it does not produce CT or MRI artifacts and the implant is more comfortable because The material is less dense and lighter in weight; unlike metal implants that can transfer heat.