A retainer with a block extending downwards from an otherwise generally flat surface is disclosed. The block corresponds to a region of one or more of the cuspids or pre-molars. A side block or other device on the upper retainer also abuts a wing or other abutment device of a lower retainer, causing the lower jaw to be pushed forward relative to the upper jaw and resting position (regular organic closing position) of the upper and lower jaw together. Thus, the upper teeth are pushed forward and a space is created between the teeth behind the (lower) block preventing an apnea during sleep.
