As the name implies, clear aligners are made of almost invisible polyurethane plastic. Rather than being cemented or bonded to your teeth as metal or clear braces are, clear aligners are completely removable — for important social occasions, for eating, and, most importantly, for brushing and flossing.
Orthodontic treatment can resolve a number of bite problems, which often become evident by age 7. These include: underbite, crossbite, overbite, open bite, crowding, or excessive spacing. To correct bite problems, teeth need to be moved. Orthodontic appliances move teeth by careful application of light, constant pressure. This force can be applied via metal wires that run through small brackets attached to the teeth (braces), or via the semi-rigid plastic of clear aligners.