Creative arch wires and clinical conclusion.
When two successive couples are present, the absolute value of the moment at each bracket cannot be clinically determined. The larger moment can be identified, however, and this will show the direction of the associated equilibrium forces. If the couples at two adjacent brackets produce moments in opposite directions, the associated equilibrium forces are also in opposite directions. The net equilibrium force present at each bracket is in the direction of the equilibrium force associated with the larger moment, but the magnitude of the force is reduced by the oppositely directed equilibrium force associated with the lesser moment. If the couples at two adjacent brackets produce moments in the same direction, their associated equilibrium forces are also in the same direction and the net equilibrium force present at each bracket is the sum of the equilibrium force associated with each moment.
Isaacson
R J
RJ
Department of Orthodontics, Virginia Commonwealth University, Richmond 23298-0566, USA.
D003799:Dental Stress Analysis; D006801:Humans; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires