: Online brands like SportingSmiles ($140 for a set), ClearRetain ($129 for a set), and Revived Smiles offer these through mail-order kits.

: You order a kit, take your own dental impressions at home, mail them back, and receive your custom-made retainer in 2–3 weeks.

: These are permanent, fixed wires bonded to the back of the teeth. While the raw wire can be bought online for as low as $10–$25 (often in packs of 10), professional installation by an orthodontist is required, typically costing $250 to $500 per arch. Industrial and Electrical Wire Retainers

The most common "wire" retainer is the , which consists of a metal wire that wraps around the front of your teeth and a customized acrylic base that sits against the roof of your mouth.