When regaining space, sometimes all the movement needs to be in one direction. Using a jackscrew with labial/lingual arch wires will give you the added anchorage you need to deliver this uni-directional force. A small dab of premixed cold-cure acrylic may also be applied to the threads behind the second nut to further ensure that the screw maintains its force and does not back up. Note: A popular option to the jackscrew is the use of a nickel titanium coil spring activated by an adjustable Gurin Lock.