The Responsibility Is Yours
The fact is that you are the person in charge of keeping your teeth straight. How do you do this? By wearing your retainers. Retainers are used for two reasons: first, to allow bone to rebuild after your teeth have moved, and second, to keep individual teeth from drifting. In other words, retainers preserve and stabilize the results you and your orthodontist achieved through your orthodontic treatment.
There are many types and designs of both upper and lower retainers. Your orthodontist has prescribed custom retainers that are best for you. But retainers can only do their jobs if you do yours by wearing them as instructed by your orthodontist.