“…Single-step 15 , 17 , 18 , 20 , 28 , 29 ( Table 1 ) or twostep impression technique 9 , 16 , 19 , 23 – 26 , 29 – 32 ( Table 2 ) is followed by many authors, but the two-step technique has the advantage of fabrication of custom tray that will reduce the amount of material needed to make final impression and also prevents excess material that has the potential to block the airway. In the two-step impression technique, preliminary impression can be fabricated with self-cure acrylic.…”