Once a skull defect unfortunately occurs, a series of problems will ensue. Cranial defects are not to be taken lightly and need to be highly alert, and early cranial repair surgery is the key. In general, cranial defect will bring the following hazards: 1, psychological problems and personality changes After cranial defect, the patient’s brain will collapse or bulge phenomenon, which has a great impact on the appearance of the image, the patient will have low self-esteem, and over time, it is easy to cause anxiety and depression. And the cranial defect also has a great impact on the nerves of the brain, and the patient’s personality will become very irritable. 2.Cranial defect syndrome If the cranial defect is not repaired, it is easy for the patient to cause secondary head injury in the process of movement, and also induce bleeding problems, accompanied by various syndromes like headache, dizziness, nausea, irritability, etc. 3.Speech and behavior disorders After skull defect, the patient’s intracranial tissues are affected by the pressure and lead to blood circulation problems, which may induce various neurological dysfunctions, such as unclear spitting and trembling of hands. From all of this, it is clear that cranial defects require early surgery to prevent various injuries from occurring. Our PEEK cranioplasty procedure is very good at repairing skull bones with a good shape. It is a good material for patients to repair their skull.