Prediction of orthodontic tooth movement

Orthodontics is rapidly advancing from the stage of fortuitous success to one of planned success. When appliance design is based on simple concepts of equilibrium, prediction of desirable and undesirable tooth movement becomes possible. The flow chart that has been presented allows the clinician to systematically treat dental discrepancies more effectively in potentially less treatment time, since the number of desirable and undesirable side effects can be known in advance and managed accordingly. Simple laws of equilibrium, based on a knowledge of the force systems required for specific tooth movement, also permit the design of proper preactivation bends for an appliance. The procedure may be enlarged to include treatment of each arch since, once the teeth are ideally positioned and rigidly held within each segment, each arch can be considered to consist of three "large, multirooted teeth."