In craniotomy, the skull is usually removed, and after the surgery, the removed skull is reset and fixed. There is a gap between the reset skull and the original skull, and the size of this gap is directly related to whether or not the bones can heal perfectly. If the gap is large and there is soft tissue embedded between the bones, the bones will not grow together easily. If the gap is not large and there is no soft tissue embedded between the bones, the bones can heal in this case. The healing time is usually about 2 years, and after 2 years, the fracture gap can be seen to have completely disappeared through CT examination, and no traces of surgery can be seen.