| 摘要 |
<p>A new orthodontic bracket comprises a bracket body (20) with a mesial-distal slot (42) for the reception of an arch wire (46 or 80) and a resilient retainer member (48) for retaining the arch wire in the slot, the retainer member being movable on the bracket body in the occlusal-gingival directions between s slotclosed position (e.g. Fig. 5) and a slot-open position (e.g. Fig. 4). The part (50) of the retainer member which closes the slot extends into the slot, so that movement of the retainer member out of the slot-closed position takes place against its resilience as the opposed embracing retainer parts are moved apart. Moreover, any force urging the arch wire out of the slot and contacting it with the retainer urges-the retainer to the slot-closed position. In the slot-open position the retainer member can be "parked" on a mesial-distal extending parking land (70) on the bracket body. A labial-extending gingival step surface (60) is provided to determine the slot-closed position and to shield the adjacent bottom edge of the retainer member. The lingual end (52) of the retainer member protrudes into a recess (66) in the base, the shape of the recess enabling the member to be moved from slot-closed to slot-open position by inserting a sutiable tool into the recess. A new arch wire (80) for use with such an orthodontic bracket has a convex curved labial face (82) and a lingual face (88) that is lingually inclined in the direction from the gingval face to the occlusal face to form a wedge shaped profile, the wire receiving slot (42) having a complementary cross-section. Such a wire provides better control of torque, while at the same time the bracket is usable with a round arch wire (46).</p> |
