Is it normal not to move the root of the tooth in orthodontic treatment?

I wore braces for about four years. The treatment plan was to move the premolar into the canine position and create a premolar space for a dental implant. At the end of the treatment, the space between the crowns was perfectly opened, but the one between the roots was not opened enough. Is this normal? Should the roots of the teeth not be in the upright position?