Bone age is the abbreviation for skeletal age, which is a developmental age obtained by comparing the actual development of a child’s bones with the standard developmental level. Bone age represents to a large extent the true developmental level of a child, so it is more accurate to determine the maturity of the human body than the actual age. The relationship between bone age and child growth and development Bone age is determined by the degree of skeletal calcification in children, and bone age is a more accurate reflection of the level of development at each age during the process from birth to full maturity. The use of bone age to infer development can provide insight into the potential for height development in children. For example, if a boy is 10 years old, but his bone age is 12 years old, it means that he is developing at a faster rate and his body is already at a physical development level of 12 years old. If the bone age is 9 years old, it means that he is developing at a slower rate and has only developed to the level of a normal child of 9 years old. There are two main methods of measuring bone age: one is a simple bone age test, which can be done at the radiology departments of major hospitals by taking a full film of the wrist bone and then performing a basic epiphyseal closure analysis to determine bone age based on the film, which is not expensive, depending on the machine used. The second is the complete bone age determination, to go to a professional bone age determination scientific institution, a series of tests and examinations, such as the Institute HDA digital bone scanning system can achieve this. Once the bone age is determined, the development is derived by comparing it with the actual age (i.e., the difference between the actual age and the bone age). If the difference between actual age and bone age is positive, it means that the bone age is behind the age; if the bone age difference is negative, it means that the bone age is ahead of the age, and there are three cases 1.Actual age – bone age = ±1 year, normal development 2.Actual age – bone age >1 year, backward development (late maturity) 3.Actual age – bone age <1 year, early development (precocious maturity) Avoid dwarfism, pay close attention to the change of bone age According to statistics, the prevalence of dwarfism in China is about 3%. According to statistics, the prevalence of dwarfism in China is about 3%, and the existing population of dwarfism is about 39 million. However, less than 30,000 patients actually receive treatment each year because parents lack sufficient understanding and attention to dwarfism. Generally speaking, if the rate of bone age increase is greater than the rate of height growth, the epiphysis will heal earlier, the growth period will be shortened, and the height will be reduced in adulthood. Under normal circumstances, when the bone age of girls exceeds 14 years old and that of boys exceeds 16 years old, the epiphysis is mostly closed and the chance of growing taller is very small. In addition, parents can also judge that if a child's height is lower than 2 standard deviations (- 2SD ) or 3rd percentile of the average height of the same race, age and gender, and the annual growth gain is less than 4-5 cm, then the initial judgment of growth retardation can be made and prompt medical consultation is needed. To prevent dwarfism, in addition to the necessary therapeutic interventions, we need to eat well, sleep well, play well, keep the habit of going to bed early, and exercise more, such as swimming, jumping rope, hanging a single pole, etc. Spring is a good season to exercise to grow taller, so we suggest parents to urge their children to eat well, sleep well and play more sports.