Below you will find the orthodontic application of the same force concepts used previously.

Center of Resistance (CR): The point of concentrated resistance to movement.

Rotation: The movement of a tooth around CR.

Moment (M): The rotation caused by a force acting at a distance from CR of a tooth.

Uncontrolled Tipping (UT): The motion created by a single force acting at a distance from the center of resistance of a tooth.

Controlled Tipping (CT): The motion of a tooth that has a force applied at a distance from the center of resistance CR and a counterbalancing couple (CBC) to regulate the rotation of the tooth.

Translation: The motion of a tooth created when a force is applied through the center of resistance (CR) or when the CBC negates the moment caused by a force acting at a distance from the CR of a tooth. Translation has no rotational component.

Counterbalancing Couple (CBC) of Orthodontics: The CBC of orthodontic tooth movement is created by the use of a twisted rectangular wire in a rectangular bracket.