The shape of the head is usually set around the age of 1 year, and the shape of the head basically does not change after the fontanelle closes. When a newborn is born, there are gaps between the bones of the skull, namely fontanelle and bregma, and the skull is relatively soft. Before the closure of the fontanelles, the shape of the head is relatively more plastic. As the child grows, the bones and brain gradually develop, and the fontanelles begin to close one after another, the bones gradually develop, and the plasticity of the head shape gradually decreases after the closure of the fontanelles, and the head shape is basically fixed. Generally, the fontanelle closes 12-18 months after birth, and individual children can delay the closure until about 2 years old, so the head shape is basically fixed at about 2 years old. Since the plasticity of the head shape is strongest at 4 months of age, if the infant has a deformed head shape, most of them can change their head shape to a greater extent by improving their sleeping position before 4 months of age. At the same time, parents need to change the child’s sleeping position from time to time to avoid causing flat head, long head or oblique head deformity, etc.