The development of each person is different, for boys there may be some who change their voice first and some who change their voice later, this is not a major sign, that is, not a major milestone of growth and development. If the epiphysis is closed in advance, it will not grow too high or the potential for growth and development will not be great. The length of the femur and the diameter of the bone determines the length of the lower limbs, and the length of the spine determines the length of the torso, so it is important to see if the epiphysis closes after the voice change.