The 3D® Quad-Helix Appliance is a multi-purpose maxillary arch development appliance that plugs into the 3D® Lingual Tube. The twin posts produce a tight friction-lock, with no free play, and .036” Tru-Chrome™ (RMO) stainless steel construction ensures both stability and flexibility. In addition to being used for traditional lateral arch development, the 3D® Quad-Helix can be used for unilateral expansion; molar rotation; molar buccal or lingual tip; molar buccal or lingual torquing; anterior advancement.