The Wilson Quad-Action Mandibular is a fixed/removable appliance designed to fit into Wilson lingual tubes, making adjustments easy. It consists of a base wire with posterior diamond loops and light wire lingual extenders that together can achieve a variety of mandibular corrections. The Quad-Action Mandibular not only effectively expands both sagittally and laterally, but is also used for selective tooth movement, as well as molar expansion, distalization and torqueing.