Braces are almost always needed, those which are used most often are:
A fixed brace
This is the most common type of brace today, often known as "train tracks". Brackets are glued onto the teeth and linked by wires.
Small elastic hoops are often used to hold the wire in position. The wires exert gentle pressure to move the teeth into a new position. The brackets can be metal, ceramic or even gold and the elastic hoops come in many colours.
A removable brace
This is sometimes used for correcting a simple problem, such as moving a single tooth or expanding the dental arch. It has a plastic plate with wires and usually springs attached. Removable braces need to be worn all the time except for cleaning or for sports.
These are used to harness the growth of the jaws and improve way the upper and lower teeth meet. There are several designs all of which fit on to both the upper and lower teeth and hold the lower jaw forward. They are mostly removable but should be worn as near to full-time as possible. These are usually worn during childhood and early adolescence.
At the end of treatment, all patients should wear retainers to hold their teeth in the new position. These can be removable or fixed and are an important part of treatment. By not wearing a retainer it is possible for a relapse to occur with the teeth moving out of position.