US Patent 7611353 Self-ligating bracket system

An orthodontic bracket system includes a bracket and a clip. During closing, an arm of the clip rides down against an inclined rear surface of a first tie wing and a portion of the clip bends resiliently, exerting a force that locks a locking edge portion of the clip in a recess beneath second tie wings. During opening, the arm rides up against the inclined rear surface of the first tie wing as the locking edge portion of the clip is removed from the recess beneath the second tie wings. The clip is then moved to an open position to permit placement and removal of the archwire and held in that position.