Well there is no peer reviewed published articles in a lengthy search that I could find relating to this. So we are in the dark here. I think the thing that we are all too aware of is that bone heals slowly and poorly after radiation, again dependent on how much for how long. Orthodontics is based on the principal that pushing against the bone (with the tooth root) will cause bone die back, allowing the tooth to move into that position and then have new bone heal in behind the tooth as the process takes place.

In kids this happens readily, and as you get older the bone's ability to do so well lessens. Adding reduced healing capacity of radiated bone to age, and you are really down to weighing the possible medical benefits you are trying to achieve vs this unknown. You sure do not want to end up with mobile teeth or pockets that become periodontal bacteria traps when all is said and done.