PositionerPositioners are special retainers that are used to maintain the positioning of the teeth as well as to achieve minor corrections. The positioner is made of a special flexible silicone in which the future positioning of the teeth is set, moving the teeth into the appropriate position. Therefore, the positioner is not a mere retainer but an elasto-aligner. Positioners must be worn over a longer period of time to achieve optimal results. A retainer is usually used after completion of the fine adjustments.