✔️ HSA / FSA eligible These are great replacement retainers because retainers are to be worn for life, and your teeth are continually shifting as you age due to bone density changes in your jaw. On top of that, teeth have a tendency to shift back after orthodontic movement. Maintain the straighter smile you've achieved for 75% less than clinics. Click here for Extra Thick Retainers  👉 Purchased from us before? click here Teeth have a tendency to shift as you age, and especially after orthodontic straightening, and retainers will prevent teeth from being crooked or spaced again. We recommend changing retainers every 6 months (because they will stretch), and to wear your retainer as instructed for life to prevent your teeth from shifting back.