Effects of wire size, loop configuration, and gabling on canine-retraction springs

Abstract

N umerous methods of canine retraction are currently in common use. These methods employ various types of attachments; wire sizes, wire configurations, sources of force application and control, and anchorage factors. The tooth may be moved distally along a continuous arch wire, which may be round or rectangular and of various sizes, The size and type of bracket affect the amount of surface area offered for contact with the wire, which may or may not significantly affect the forces transmitted to the periodontal ligament. Space closure may be accomplished by means of buccal sectional closing loops, eliminating any possible effects of friction but sacrificing some measure of tooth control. Forces may be applied through the use of latex elastic thread, open or closed-coil springs, wire loops of numerous designs, and a number of headgear types currently available. Anchorage may involve many combinations of intraand intermaxillary tooth units, muscular forces (lips, tongue), bone types (cortical, spongy, osteoid) , and extraoral (cervical, occipital) resistance factors.