Braces (orthodontic treatment) straighten or move teeth to improve the appearance of the teeth and how they work. Braces can be removable, so you can take them out and clean them, or fixed, so they're stuck to your teeth and you cannot take them out. They can be made of metal, plastic or ceramic. Invisible braces are made of a clear plastic. Braces are available on the NHS for children and, occasionally, for adults, depending on the clinical need.