Babies with flattened heads have a chance to grow back and need to be corrected before the fontanels close. The best age to adjust the baby’s head is around 3-4 months of age, when the skull is not yet very hard and the fontanels are not yet closed, which is the best time to sleep with the head shaped. If you miss this period, it does not matter, within one year of age, the skull is not yet fully calcified, sleep to the other side of the side or alternating between the left and right sides of the sleep, most can be corrected. There are also some infants may be due to vitamin D deficiency rickets caused by the softening of the skull, resulting in infants head shape is not round, it is recommended to strengthen the vitamin D supplementation, appropriate increase in outdoor activities, and more sunshine, to promote calcium absorption, and strengthen the cranium.