Dental braces (also known as braces, orthodontic cases, or cases) are devices used in orthodontics that align and straighten teeth and help to position them with regard to a person's bite, while also working to improve dental health. They are often used to correct underbites, as well as malocclusions, overbites, open bites, deep bites, cross bites, crooked teeth, and various other flaws of the teeth and jaw. Braces can be either cosmetic or structural.
Dental braces are often used in conjunction with other orthodontic appliances to help widen the palate or jaws and to otherwise assist in shaping the teeth and jaws.
The application of braces moves the teeth as a result of force and pressure on the teeth. There are traditionally four basic elements that are used: brackets, bonding material, arch wire, and ligature elastic. The teeth move when the arch wire puts pressure on the brackets and teeth. Sometimes springs or rubber bands are used to put more force in a specific direction.
When braces put pressure on teeth, the periodontal membrane stretches on one side and is compressed on the other. If this movement is not done slowly then the patient risks losing his or her teeth. This is why braces are commonly worn for a year or more and adjustments are only made every few weeks. A tooth will usually move about a millimeter per month during orthodontic movement, but there is high individual variability.