title: [Ricketts' Quad-Helix in clinical practice].
mesh_terms: D000202:Activator Appliances; D004867:Equipment Design; D006801:Humans; D008310:Malocclusion / Q000628:therapy; D009968:Orthodontic Appliances, Removable; D010155:Palatal Expansion Technique / Q000295:instrumentation*
vernacular_title: Il Quad-Helix di Ricketts nella pratica clinica.