The quad helix appliance.

Along with the utility arch and sectional mechanics, the quad helix appliance has become an integral part of the Bioprogressive technique. The quad helix is mostly used to unlock malocclusions and to establish normal function and arch form by expanding the dental arches. It is also a useful adjunct in the treatment of Class II malocclusions and mostly in those cases in which molar derotation is required as part of the treatment. Expansion of the alveolar ridges is only undertaken after correlating measurements taken from the study casts with those obtained from frontal cephalometric radiographs. In terms of dental arch alignment, a quad helix can achieve in 3 to 4 months what would otherwise take a great deal longer and at least a series of arch changes.