We'll divide this answer into two parts. First, you should know that patients who wear removable retainers need to wear theirs for up to 22 hours every day for the first few months after they complete their orthodontic treatment. Then, they can wear their retainers only at night. Second, patients should know that there's no definitive time frame that determines how long they'll have to wear retainers and then forget about them entirely. Instead, you might have to wear retainers for life and prevent any unwanted or accidental shift in tooth position.