Orthodontic braces are devices that are used to straighten teeth and correct misaligned bites. They consist of brackets that are bonded to the fronts of the teeth, and a wire that runs through the brackets. The wire is held in place by small rubber bands, called ligatures, or by small metal clips called brackets. The wire is adjusted periodically by an orthodontist, who tightens it to apply pressure to the teeth and gradually move them into the desired position. ​ Orthodontic braces are usually worn for an extended period of time, typically one to three years, depending on the severity of the misalignment. They can be made of metal, ceramic, or plastic, and can be worn on the fronts or backs of the teeth. In some cases, invisible aligners, such as Invisalign, may be used as an alternative to braces.