Parents of patients, and even some medical practitioners, often ask, “Can children with cranial defects be repaired, when and how can they be repaired, since their skulls are still growing and developing? To answer these questions, we need to review some history first. Traditionally, it is believed that children’s cranial bone changes a lot with age, and the stability of artificial material fixed on the undeveloped children’s cranial bone is poor; moreover, as children grow up, the area of cranial defect becomes larger, and there is a possibility of repair material falling off; after early repair, the repair material will hinder the normal growth of cranial bone and cause asymmetric development of cranial bone, which will affect the development of brain tissue and the beauty of skull shape, so early cranial repair is generally not advocated. Cranial repair is not recommended. However, in recent years, more and more clinical and basic researches have gradually revised the traditional viewpoint and supported the appropriate relaxation of surgical indications, and the early surgical repair of cranial defects in children has been increasing. (1) As all systems of the body are growing and developing in childhood, cranial defects have the tendency to grow and repair by themselves, and it is usually believed that cranial defects within 3 cm in diameter have the possibility of self-healing, but for cranial defects larger than 3 cm in diameter, most of them will not heal by themselves and dural calcification often occurs. Dural calcification can limit the development of the brain. (2) Cranial defects disrupt the normal physiological balance in the cranial cavity, causing cerebral blood vessels in the defect area to dilate and slow down the blood flow, and local blood flow stagnation in the brain; at the same time, the cranial defect can become larger with development, and the edges of the defect are turned out, and the protruding brain tissue shows progressive atrophy, hydrocephalus and cystic degeneration, which affects the normal development of brain tissue. (3) Longer cranial defects can lead to increased deformation of brain structures due to pressure imbalance in the intracranial physiological space, resulting in displacement or distortion of the midline brain structures, enlargement of the ventricles and protrusion and deformation to the defect area, even causing cerebral penetration malformation, and increasing the incidence of epilepsy, thus seriously affecting the normal recovery of neurological functions. (4) Because the local brain tissue loses the bony barrier, coupled with the child’s lively and active behavior, it is easy to cause re-cranial brain injury. (5) It is easy to cause dizziness, headache, fear, discomfort in the defective area and other cranial defect syndrome, which affects their social activities. (1) Cranial defect not only hinders the aesthetic appearance, but also causes psychological pressure to the children, especially school-age children often have insecurity, so early cranial repair can make the children recover normal psychological state quickly. (2) Early repair can protect the brain tissue in the defective area from re-injury, and create good conditions for further growth of new bone and ideal skull with normal physiological curvature. (3) 1-3 months after injury is the fastest period of neurological recovery, and early restoration of the integrity of the cranial cavity is a prerequisite for further recovery of neurological function, which not only improves the hemodynamics of local brain tissue, but also relieves the compression of brain tissue in the defect area by atmospheric pressure. It has different degrees of promoting the recovery of limb paralysis, aphasia, mental or intellectual impairment associated with the injury site that occurs later in some children with craniocerebral injury. (4) Relieve the cranial defect syndrome. (5) Preventing secondary atrophy, cysts and brain penetration malformation formation in the defect area and avoiding further neurological damage. (6) Long-term cranial defect, the local formation of meningeal scars or ossified structures can cause headache and seizures. 3, the timing and feasibility of early repair of cranial defects in childhood: most scholars believe that the minimum age of repair is 4-5 years old, and individual reports indicate that cranial repair is performed at the age of 2 years old, and some studies show that the immature cranial bone has strong self-regulation ability under the condition of external restraint, and the cranial bone can conform to the normal cranial morphological growth. Therefore, the age of repair can be further relaxed to 2 years old due to the rapid motor development of infants and children above 2 years old, the increase of injuries such as accidental falls, the presence of cranial defects that increase the risk of brain injury, and the fact that the skull of infants and children above 2 years old already has a certain thickness that can adapt to the length and firmness of titanium nails. If infant and child anesthesia and monitoring techniques are available and appropriate repair materials are selected, there is no need to adhere to a certain age limit. The timing of cranial defects varies among scholars, ranging from 1-6 months or more after debridement and decompression surgery. At present, most of them prefer to operate around 1,5-3 months after cranial defect, provided that the first surgical incision has healed, the intracranial pressure is normal, the decompression window tension is not high, and the condition has been stabilized. 4.Material selection of cranial repair in childhood: cranial repair is a plastic surgery, in addition to the selection of good repair materials, we should also pay attention to the aesthetic effect of the postoperative shape, children’s scalp and skull are thinner and in the developmental stage, so the requirements of surgical materials are more strict. There are three types of cranial repair materials: autologous bone graft, allogeneic bone graft and foreign body graft, among which the research on foreign body graft has received the most attention. The literature reports that the application of autologous materials in cranioplasty in children and adolescents can cause up to 50% postoperative resorption of the autologous material, which requires reoperation and can easily cause up to 10% infection. The most ideal and commonly used foreign body graft material is currently recognized as malleable titanium mesh. Titanium products have many advantages: light and thin, strong plasticity, even if used in special parts of the skull, it can make it close to the edge of the skull defect; it has sufficient mechanical strength, stable chemical properties, good histocompatibility; good paramagnetic adaptability after implantation, and does not affect CT, MRI, DSA and other examinations. Therefore, titanium mesh material was selected for this group of cases, and computerized three-dimensional shaping technology was applied on this basis to achieve more ideal surgical results. Computerized three-dimensional shaping technology uses the patient’s cranial CT data information and applies computerized three-dimensional reconstruction technology to carry out three-dimensional reconstruction of the defective skull and realize personalized design through digital design, surface reconstruction and virtual assembly. It makes the repair titanium mesh conform to the maximum physiological anatomical shape of the patient’s head, especially the cranial repair at the frontal, supraorbital rim and frontotemporal areas, and creates a completely personalized titanium mesh restoration, so that the postoperative repair titanium mesh can restore the patient’s original appearance and shape to the maximum extent to ensure a perfect repair. In this group of cases, the operation time was significantly shortened, reducing the chance of contamination and the risk of surgical infection. No postoperative complications such as fluid accumulation under the flap, loosening of the dowel, or topping of the titanium mesh edge through the skin occurred, and the satisfaction of appearance reached 100%.