| 摘要 |
The invention provides an orthodontic bracket having a base portion configured for attachment to a mounting device such as a bonding pad that is directly secured to the tooth of a patient. A central portion of the bracket adjacent the base portion has a pair of sides that taper to a minimum diameter at a midline of the central portion, preferably giving the bracket an hourglass shape. A pair of single tie wings extend in gingival and occlusal directions respectively from the central portion, which tie wings define outer end portions that are wider than the central portion and have undersurfaces positioned for mounting archwire retaining bands therein. An outwardly opening archwire slot elongated in the mesial direction is formed in the central portion, which slot extends at an acute angle relative to an imaginary line extending in a buccal-lingual direction such that the slot opens closer to the gingival tie wing than the occlusal tie wing. An inner end portion of the occlusal tie wing overhangs the archwire slot. This bracket has a simple shape yet provides optimum interbracket distance as described hereafter, which distance is especially important when an orthodontic appliance using the bracket is to be mounted on the lingual side of the teeth where the curvature of the archwire is more severe.
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