An oral appliance may include a first jaw retainer piece, a second jaw retainer piece, a holding member, and a rod. The holding member may be mounted on a front-facing portion of the first jaw retainer piece, and have an opening for receiving a rod. The rod may have a leading end slidably inserted into the opening of the holding member and a trailing end mounted on a front-facing portion of the second jaw retainer piece. The oral appliance may further include a restrictor that restricts sliding of the rod relative to the holding member.
