The epiphysis is not closed at the age of 20, boys can still grow taller. This is due to the fact that some boys with relatively delayed growth and development have their epiphyses close relatively late, making it possible for them to continue to grow taller; you can determine whether the epiphyses are closed or not through X-ray images, which can indicate whether there is still a possibility of growing taller. To determine whether the epiphysis is closed, you can go to the hospital and take an orthopantomogram of the left knee joint and observe whether the epiphyses of the femur and tibia have disappeared, in order to determine whether the epiphysis is completely closed; the start of puberty varies from child to child, and children who have hormonal changes relatively late in life have a relatively delayed growth, which can result in a male who has not yet had his epiphyses completely close at the age of 20 years old. For boys who have not yet completely closed, through different levels of intervention measures, and promote the growth and development of the bones, so that the increase in height; secondly, you also need to maintain good habits, regular work and rest, strengthen the nutritional intake, growth and development abnormalities in a timely manner to avoid developmental disruption.