Due to the impact of the declining birthrate in recent years, many parents hope that their children can win at the starting point. Among these, children’s height has gradually become an issue of concern to parents. In addition, in school, many people often feel pressured by comparisons with their peers. Therefore, there are many cases in the pediatric clinic where parents request to have their bone age checked. However, in the outpatient clinic, I often ask parents why they want to check their bone age at this time? Most people couldn’t answer the question. Just because their neighbor’s classmate had a certificate, they all wanted to come to the hospital to arrange an examination.
There are even cases where a 17-year-old boy whose voice has changed for 4 years comes to ask for a bone age test, etc. that goes beyond medical standards. Before arranging bone age examination, we should have a good understanding of the normal growth process, so as to know who needs bone age examination and avoid the waste of medical resources.
Growth rates vary greatly in different periods
For patients with short stature, it is recommended to prepare records of height, weight, head circumference, birth weeks and birth weight over the years before consultation. Most of the height of a newly born full-term newborn will be around 50 centimeters. The average length in the first year of life is 25 cm. The average length in the second year of life is 12.5 cm. Before entering puberty, the average growth rate is at least 4-6 centimeters per year. In the first 3 years of life, the most critical factors for infant growth and development are adequate nutrition and thyroid hormone. Adequate nutrition can prevent infants and young children from iron deficiency anemia or rickets caused by vitamin D deficiency. Thyroid hormone is a key hormone for brain development during this period. After entering elementary school, the role of growth hormone becomes more and more important.
Puberty is stimulated by sex hormones, and boys and girls behave very differently. On average, girls begin to develop breasts when they are 8-13 years old. After breast development, menstruation will occur on average 2.5-3 years later. The fastest time for girls to grow taller is one year before menstruation. On average, they can grow about 8 centimeters a year. After menstruation, the growth rate begins to slow down, and there may be only 5-11 cm of growth space left. It is generally believed that the average female bone age heals at 14 years old.
Puberty generally starts later in boys than in girls. Testicles and penis begin to develop between the ages of 9 and 14. Then the beard, pubic hair and armpit hair begin to grow. Finally, at the age of 13.5-14 years, the maximum growth rate can be reached one year before voice change and Adam’s apple growth. During this period, the growth can reach 10 cm in 1 year. It is generally believed that the average male bone age heals at 16 years old.-