The CD Multi-Action Hyrax constitutes another solution for accomplishing distal bodily movement of the first molars while expanding the arch laterally. It incorporates the use of NiTi coil spring, compacted onto buccal and lingual bars that run from the bicuspids to the molars. The bars are soldered to the bicuspid bands and run through tubes which are soldered to the molar bands. As the coil expresses itself, the molars slide distally along the bars in a bodily fashion. Note: Once molar position is established (and the arch is expanded), a holding arch is usually placed. The bicuspids and cuspids are brought back in the arch form -- one at a time -- using fixed mechanics.