By growing taller, we mean the linear growth of bones. People keep growing cartilage at both ends of the long bones before the completion of youthful development, so that the bones grow longer, and the bone scale line closes in adulthood, and people do not grow taller. There are three ages for children in growth spurts: the actual age, the height age (i.e., height equivalent to the average of 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 the bone age, and the combination of age, bone age, height and development can 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. A child, male, 13 weeks old, 159 cm, was seen for recent slow growth. His father was 176 cm tall and his mother was 159 cm tall. According to his parents, the child’s height had been in the low end of the normal range since childhood, and because both parents were of normal height, they always thought they could catch up by the developmental period. Three years ago the child began to grow faster and the parents were still satisfied. About a year and a half ago, the child began to change his voice, and then it became obvious that the growth rate was slowing down. After examination by the doctor in the specialist clinic, the child’s sexual development had basically matured, and the bone age was 16 years old, with room for growth of about 2 cm. In terms of height alone, the child is currently normal compared to his peers, but considering the degree of development and bone age, his final height is around 161 cm, which is very undesirable compared to his genetic height.
Due to genetic, environmental, nutritional, and disease factors, the actual age and skeletal age of children often do not coincide, and more so in children with precocious puberty, where the skeletal age exceeds the actual age by generally more than one year. The prediction of adult height is based on the actual height of a child’s skeletal age, so that we know how long the child has before the end of growth, so that we can give targeted compensation to obtain the relatively ideal height in clinical practice. In the diagnosis and treatment of children with precocious puberty, it is particularly important to track the dynamics of individual bone age.