l had braces nearly 2 years ago and wore a retainer (the plastic invisaline looking ones) day and night time for a few months, now l wear it only at night. even though i've been wearing it every night my teeth are going crooked :( my top middle teeth especially.
i've shown my orthodontist but she was not very helpful..

What can l do to stop them from going more crooked?
how many hours should l be wearing my retainer etc?

Get a new orthodontist.

you better get a second opinoion

Does the retainer still fit? Maybe you should wear it more, or just wear it every other day instead of only nights. You could try doing every other day and nights, and then twice a week and nights, once a week and nights, just nights, etc. so that your teeth get used to this.
l do not know if this will work. l am not an orthodontist.. But maybe it is worth a shot!

Your orthodontist might have taken your braces off early in the past not giving them time to stabilize and get used to there new positions to stay that way. you might as well ask for a new retainer to see if over time it has become loose or different. good luck

Switch orthadontist.

Teeth will naturally shift back to their original position if you do not wear your retainer enough. Wear your retainer just like you did when you first got your braces off for a few weeks and see if they move back. Then try going back to part time wear, but I'd put it in after dinner and wear it through the night.

You should know first of all that those kind of retainers are really crappy. l still have my braces on and plan to get the permanent kind they put on the back of your teeth. Even my dentist is assistant said it was a crappy kind of retainer to get because it can stretch out and lose its shape. Get a new orthodontist.

The exact same is happening to me! and my dentists did not help?
There is not much you can do unfortunately but if you wear your retainer they can not move that much and if your dentist is not worried then you really have no reason to be either. Are your retainers cracked or loose if so then you should tell your dentist because your teeth will be moving. Just wear your retainer for the time your dentist told you to thats really all you can do. Hope l helped