Question
When does a child’s braincase grow to its full size, also known as closure?
Answer
The size of the fontanelle is closely related to the development of the brain. Microcephaly and the shrinkage of the fontanelle due to poor brain development can nearly close it. Microcephaly can be caused by factors such as chromosomal abnormalities, metabolic diseases, intrauterine infection, and intrauterine malnutrition. By the fifth month of pregnancy, the brain development of the fetus has already shown delays. At birth, the head circumference is slightly smaller than that of a normal newborn, with a small fontanelle or nearly closed. With age, facial bone development becomes normal, while the frontal bone and the two sides of the zygomatic bone tilt upwards, the occipital bone flattens out, and the skull becomes smaller, with a pointed top, hence also known as acrocephaly.