A resilient orthodontic appliance designed to move the teeth in a controlled and predetermined direction and used for finishing orthodontic cases. It is designed to achieve minor correction of sagittal plane arch relationship discrepancies. The appliance fills the freeway space, and covers the clinical crowns of all the teeth and about 3mm of the buccal and lingual gingival mucosa. It is constructed over a predetermined ideal tooth configuration and fabricated from either plastic or a flexible material. See also invisalign.