Parents often bring their children to the clinic to see “microcephaly”, and even some specialized doctors say that there are many, many cases of microcephaly surgery in a year. It should be noted here that microcephaly and craniosynostosis are two different things. Not only are the causes and mechanisms different, but the treatment methods are also different, and the prognosis is also quite different. What we call microcephaly in medicine can also be called premature closure of the cranial suture. There are many sagittal sutures and frontal sutures in the normal human skull, and the coronal sutures and herringbone sutures that grow symmetrically on both sides of the skull. However, if for some reason, including genetic, environmental, hereditary, or something that is still unclear, one or more of the sutural sutures are closed, then the two skull bones adjacent to the sutural suture will not grow, and the rest of the skull will expand compensatingly, resulting in abnormal head shape. The most common form is navicular head due to premature closure of the sagittal suture, and there are also flat head, oblique head and tower head. The non-growth of the skull leads to limited development of the brain tissue beneath it, which slowly leads to increased intracranial pressure, protruding eyes and mental retardation in some children. Therefore, if the bone suture is reopened or the skull is opened and reshaped, it will relieve the pressure of the deformed skull on the brain tissue, promote the development of the brain tissue, and improve the appearance of the deformity, and its prognosis is still very good. On the contrary, most microcephaly is caused by intrauterine hypoxia, infection, intracranial hemorrhage, and other causes of brain tissue dysplasia. Because the brain does not grow, the skull loses the power to expand, resulting in a small head. In this case the bone gap is present in the child and the underlying cause is a problem with brain development. Therefore, cranial surgery is not useful in this case, and only promoting and improving the development of brain tissue can solve the problem. However, there is no specific treatment for brain development and many of the nerve damages are irreversible, so the prognosis for such children is often poor.