For a pit on the top of the head, if it is a newborn or pediatric, it can be considered a normal phenomenon, because the newborn cranial parietal bone is not yet fully developed, the gap between the bones is not closed, but full of fibrous tissue membrane, the connection between the cranial parietal bone will form a gap, medically known as the cranial fontanel, and this gap will be gradually closed with the development of the slow and gradual closure. If a mature adolescent or adult still has a skull fontanel on the top of the head, it may be late development or imperfect development, it is recommended to go to the orthopedic department of the regular hospital in time to take appropriate treatment measures, which may require orthopedic or other surgical treatment.