 The plate is only found in children and adolescents; in adults, who have stopped growing, the plate is replaced by an epiphyseal line.This replacement is known as epiphyseal closure or growth plate fusion.Complete fusion happens on average between ages 12–18 for girls (with the most common being 15-16 years for girls) and 14–19 for boys (with the most common being 18-19 years for boys).