Many patients are concerned about the dangers of cranial defects when they are caused by various reasons, such as whether they will be afraid of heat and what damage they can do to the brain. Here is an answer to these common concerns. Cranial defects can be very harmful, not only to the brain, but also in the whole body may show a series of uncomfortable symptoms, called “cranial defect syndrome”. How does a cranial defect damage the brain? Cranial defects are very common in neurosurgery clinics, and can be caused by trauma such as traffic accidents, workplace accidents, falling from height, or left over after craniotomy for intracranial tumors, cerebral hemorrhages, and other cranial diseases. What is the damage of cranial defects to the brain? The harm of cranial defect lies in destroying the integrity of the skull, the closure of the cranial cavity and the stability of the intracranial environment, thus causing cerebrospinal fluid circulation and blood circulation obstacles, affecting the normal operation of the nerve function and causing a series of neurological symptoms. Some patients may manifest as dizziness, headache, limb weakness, poor fine activities, weakened vision, emotional instability, irritability and so on. Is craniosynostosis a fear of heat? As for whether cranial defects are afraid of heat, we have not encountered any patients reflecting this kind of situation in clinical work, and there are no relevant reports in the literature. However, there is a common fear of heat in patients who have used titanium mesh for cranial defects, and these patients tend to be afraid of heat. Because titanium mesh is a metal material with strong thermal conductivity, if the external environment is hot, it is easy to conduct through the titanium mesh to the skull, and if under strong sunlight, there may even be burning, burning sensation. In addition, it is because of the heat conduction effect of titanium mesh material, titanium mesh repair of the skull after the patient will also be more afraid of cold. In addition, titanium mesh skull repair has some other defects and shortcomings, such as postoperative infection, rejection, wear and tear of the scalp, titanium mesh exposed, easy to deformation and collapse, affecting the CT, MRI examination and so on. Therefore, it is not recommended to use titanium mesh material for cranial bone repair. At present, there is a new type of special polymer material – polyether ether ketone PEEK material, performance is very excellent, PEEK material does not conduct heat, the patient will not be afraid of heat and cold, in addition to the hardness, stiffness, strength, elasticity, tissue compatibility of PEEK material and autologous cranial bone are comparable to the titanium mesh material can be very good to overcome the above problems may arise. In addition, the hardness, stiffness, strength, elasticity and tissue compatibility of PEEK material are comparable to that of autologous skull, which can well overcome the above mentioned problems of titanium mesh material, and it has become the new trend of cranial bone repair material.