To apply the label of classical [[Scheuermann's disease]], the Sorensen criteria need to be met 
((Sørensen KH. Scheuermann's juvenile kyphosis. København: Munksgaard 1964:222-4))

thoracic spine kyphosis >40° (normal 25-40°) or
thoracolumbar spine kyphosis >30° (normal ~zero degrees)
and

at least 3 adjacent vertebrae demonstrating wedging of >5°