What Do Braces Do?
Braces are a device used to straighten teeth, to correct a bite and to correct irregular teeth. They are made of three basic parts: brackets, bonding (or band), and an arch wire. The brackets are fixed to the teeth with the bonding. The arch wire is run through the brackets and is held in place with small rubber bands.
The brackets and arch wire work together to move the teeth into new positions that will correct your bite, straighten your teeth, correct gaps, etc. The arch wire puts pressure on the brackets with distribute the pressure to the entire tooth, and the orthodontist uses the arch wire to dictate how the teeth are moved into their new positions. When your teeth have pressure applied to them, the membrane that surrounds the roots of the tooth expands on one side and constricts on the other, causing the tooth to loosen from the gums. When the tooth stops moving, the bone around the membrane grows in to provide support to the tooth in its new place. This movement needs to be done slowly otherwise you risk losing your teeth. This is why braces are commonly worn for two to two and a half years and adjustments are only made every three or four weeks.
The reason this works is because arch wires are wires that want to keep their original shape and will exert a great deal of force to return to their original arch shape. The materials used to make the arch wire increase their stiffness when exposed to your body heat. It is the combination of your body heat and the desire of the arch wire to keep its shape that provide the wire with enough strength to pressure your teeth to move.
Braces alone, however, are not always able to do the work by themselves. Sometimes your orthodontist will also use rubber bands to manipulate the pressure to pull the teeth in the correct direction. Other times, your orthodontist will require you to wear headgear. Headgear keeps some teeth in place while allowing others to move, and to enforce the alignment of the teeth as they move into their new positions.
Another part of the braces process is the Retainer, which needs to be worn after your braces are removed, to hold the teeth in their fixed positions.