I had my braces taken off in early 2012. I have a hawley retainer. Somehow, my upper teeth have shifted a little bit. If you look at me, the tooth on the right of the right front tooth has gone behind the right front teeth. My mouth feels fine with the retainer in my mouth. Overtime, will the teeth shift back to normal? I realize I somehow messed up and any input is welcome.

Your wire may have bent. Aren't you seeing your orthodontist for follow-up visits? If not, make an appointment.