How do braces work?
A set of braces consists of two parts: 1) the brackets — which are the “handles” attached directly to the teeth and 2) the wires — which are positioned in the slot of a bracket and apply pressure to the teeth. Traditional metal brackets are made of special medical grade stainless steel or titanium, while clear (or tooth colored) brackets are made of ceramic. Lingual braces are made of metal and attached to the back side of the teeth (tongue side which is why we use the term “lingual”). The wires can be held into the bracket in a number of ways. They can be tied into place using a very small and soft wire, with a colorful elastic tie, or possibly with a small door that is a part of the bracket. Once the brackets are attached, they remain in place for the duration of treatment (unless a patient breaks them by eating hard or sticky food!). The wires and ties are changed throughout treatment.
If the brackets are the “handles,” the wires are what actually cause the teeth to move. The initial wires are most often made of a nickel titanium alloy. This alloy was developed by NASA for antennas on space satellites. When a rocket launches, antennas can’t protrude because they would burn away on takeoff. Instead the antennas are made of nickel titanium alloy with “shape memory.” This means the alloy “remembers” the shape it wants to have. So an antenna can be coiled up in a compartment, but after launch, the compartment opens and an antenna will immediately straighten out into its pre-determined shape. Here on earth, we use this amazing ability in orthodontics! We place a small nickel titanium wire into the brackets of very crowded teeth. The wire “remembers” how it wants to be shaped (i.e. straight) and puts pressure on the teeth as it works to straighten out. Pretty cool, right?! This means a consistent light pressure is applied to the teeth, making 21st century braces much more comfortable than braces of the past. Using the same approach, wires can be made of many different materials and shapes, allowing more and more precise control over the position of your teeth.
Sometimes we do need to use additional appliances beyond just braces. You can learn more about these below.