How braces work
Braces (or brackets) are glued on to the teeth. They act as "handles" to which arch wires can be attached.
A distorted arch wire exerts a force on each tooth and, as it returns to its ideal, pre-formed shape, it moves the teeth to which it is attached through the bone.
Each bracket is "tailor made" for a specific tooth and progressively thicker and stiffer wires are used to gradually align the teeth.
Eventually, the entire arch of teeth is in correct position in all three planes of space.