When do you use a figure spring vs. a jackscrew to move teeth in a removable appliance?

By Dr. Vishaal Bhat on Tuesday 15 December 2009 with 0 comments



This photograph of a smile exhibits a pink too...Image via Wikipedia

In contrast to the heavy, rapidly decaying forces produced by a screw, nearly optimum light continuous forces can be produced by springs in a removable appliance. Like the edges of an active plate, however, these springs contact the tooth surface at only one point, and it is difficult to use them for anything but tipping tooth movements. The guideline for tooth movement with a spring from a removable appliance therefore is that this is acceptable for a few millimeters of tipping movement. Root control is needed for more than 3-4 mm of crown movement. One possible use of a removable appliance is to retract flared incisors, and for this purpose a long labial bow with loops for greater flexibility and adjustment is normally used.
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Category: Orthodontics Notes

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