After craniotomy, it usually takes about 3 months for the skull to grow back completely. In clinical practice, the skull is relatively fixed after craniotomy, that is, the connecting piece or connecting plate is applied to fix the skull accordingly, so as to protect the skull from being collapsed by very slight external force, which is a relatively safe state. This is a relatively safe condition, unless a second traumatic injury is sustained at a later stage, which is very strong and may cause the skull to deform, resulting in more adverse effects. In general, however, if there is no particular problem, as is usually the case with side pressure on the skull while sleeping or a slight bump on the skull, it takes about 3 months for the skull to really grow back and that is enough. However, care must be taken to protect the skull accordingly and minimize this irritation. The healing time does not develop as a rule if there is diabetes, hypoproteinemia, etc.