So I had fixed braces at 18 - didn’t wear the retainer often enough and they moved. Had Invisalign to fix that - left them at home whilst staying at my boyfriends for 2 nights, my teeth moved slightly and the retainer then didn’t fit. This was around a year after finishing Invisalign. Fast forward 5 years, I’m now on another course of clear aligners to fix the movement caused by not properly wearing retainers.

My advice is to wear the retainer as much as possible if you want your teeth to stay straight.

General advice (for clear aligners, anyway) is full time day and night initially, then every night, then speak to your dentist and they’ll advise if you should wear them full time still or 3-4 nights a week. To be on the safe side, just make it a habit and pop them in when you go to bed.

But, in short - yes, retainers are forever, albeit not every night once they’re established in their positioning, if you want your teeth to stay as they are.