The problem with retainers is it's very difficult to control the movement of teeth in all three planes of space ( horizontal, vertical and lateral direction).Originally Posted by wirelessfries
For your upper, it's fortunate your happy with the result. It doesn't always end up that way though.
A retainer is meant to hold teeth, not move them.
It is your choice in the end, I'm just giving you options and suggestions so you can make an informed decision.
Best of luck to you.