The normal height of a girl at the age of 11 weeks is 146.6 cm. Most girls at the age of 11 weeks have already entered puberty or started to enter puberty, which is characterized by the development of secondary sexual characteristics such as breast development, etc. At this time, the child’s height may be affected by estrogen, which may lead to early growth or sudden increase in height. Therefore, to measure the normal height of a child, a bone age examination should be performed, i.e., an orthopantomogram of the left wrist joint, to clarify whether the actual height of the child is consistent with the height of the bone age. If it is approximately normal or within 1 standard deviation up or down there is no problem. If the difference between the actual measurement of bone age and the actual height is more than 2 standard deviations, or if the child’s height is below 138cm, the child is considered to be short, and further examination related to short height should be carried out for the child to avoid the phenomenon of too short due to missing the best treatment period.