| 摘要 |
New orthodontic devices comprise a bracket or convertible buccal tube, both having a body with an arch wire slot (26) therein. Both have a slot closure member (36), also referred to as a jamming shutter, pivotally mounted for movement between slot open (Fig.2) and closed (fig.1) positions and consisti ng of a pivot portion (46) including an arm portion (50) with a mesially-distal ly extending slot closure portion (48) at its end. The slot closure portion (48 ) has a part that closes the slot and mesially-distally extending parts that i n slot closed position (Fig.1) engage an adjacent body surface with an interference jamming fit sufficient to retain the slot closure member (36) i n slot closed position (Fig.1). Any movement of the slot closure member (36) t o and from the slot closed position (Fig.1) involves flexing of these engaged parts away from the device body against the material elasticity, removing th e need for latches or retaining springs. The body or the closure member has a recess (54) to receive an opening tool (58) that is rotated to open the slot . A bracket will usually be "active", including an attitude controlling spring (64) having a free end (68) protruding into the slot (26). A surface of the pivot portion (46) can be a cam (82) that in slot open position (Fig.2) hold s the spring (64) out of the slot (26), facilitating insertion and removal of the wire. In brackets for incisors or canines the labial-lingual dimension decreases progressively from the lingual to the labial; with the slot closed the occlusal surface is unobstructed and forms a bite plane engaged by the cutting edge of the opposed tooth during biting action to oppose overbite. A convertible buccal tube employs the same basic structure with the slot openi ng at an appropriate surface; the slot closure member (36), and a spring (64) i f provided, are similarly mounted in the body.
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