A person’s growth depends on the growth of bones, mainly the growth of long bones, such as the bones of the lower limbs and thighs. The cartilage at both ends of the long bones grows continuously before the completion of youthful development, making the bones long, and the bone scale line closes in adulthood, and the person does not grow taller. There are three ages for children in growth spurt: the actual age, the height age (i.e., the average of height equivalent to several years old children), and the bone age. Medically, the maturity of bones can be judged by observing the process of bone growth, thus predicting growth potential, i.e., there is a reliable scientific basis for predicting height by bone age.
Therefore, the physical examination of children should include bone age, combining age, bone age, height and development in order to comprehensively judge their growth and development and predict their adult lifetime height. It is inaccurate to predict a child’s adult lifetime height solely based on the parents’ height; this calculated height is called genetic height, which is only one aspect of determining a child’s height. A physical examination that looks solely at actual age and height is not comprehensive.
Due to the influence of genetic, environmental, nutritional and disease factors, the actual age and bone age of children often do not coincide, and the bone age of children with short stature is often more than one year behind the actual age. The prediction of adult height is based on the actual height of a child’s bone age, so that we know how long the child has before the end of growth, so that we can give targeted compensation to get the relatively ideal height in clinical practice.
How to determine bone age is so important: First, take an orthopantomograph of the child’s left hand, then have the doctor evaluate the bone age and estimate the child’s likely final height based on the bone age and actual age.