Every case is different. Some people need to wear them every night, while others will be able to wear them for more limited periods of time. Other people will find that unless they wear retainers all day, every day, their teeth want to move back to their previous positions. If after 6-12 months, you find that your teeth are still moving when you don't wear your retainer,  we recommend that you see your regular dentist or orthodontist to get a permanent retainer made.