Orthodontic apparatus and method

摘要

An orthodontic device includes a bracket having a body and the body includes external surfaces. An archwire passageway is formed in the body. An aperture extends from one of the external surfaces of the body to the passageway. A pawl is attached to the body and includes stop and cam surfaces which extend into the aperture. An extendable archwire includes an adjustment portion having a locking surface and a loop-spring therein and the adjustment portion is inserted into and through the passageway. The pawl and the locking surface form a ratchet. The cam surface of the pawl interengages the extendable archwire as the extendable archwire is extended through the bracket under the application of force to the extendable archwire. The stop surface of the pawl interengages the locking surface of the adjustment portion of the extendable archwire preventing retraction of the extendable archwire upon discontinuation of the application of force.