A plurality of self-ligating orthodontic brackets for use in orthodontic treatment comprising at least one first bracket, at least one second bracket, and at least one third bracket. Each of the first, second and third brackets include a first, second and third locking shutter, respectively, for applying a force onto an archwire to effect orthodontic treatment. The first locking shutter applies a first force, the second second locking shutter applies a second force and the third locking shutter applies a third force such that the first, second and third forces differ from each other.