I can't believe you're telling me to do this if I want to build range and endurance without knowing anything about me or my students. You do appear very cocky saying that ALL my students range problems will disappear. Well they don't have any issues with range or endurance. Taking your finger and moving your lip with it ,is an embouchure change not a minor adjustment. Besides I have never seen or heard of any player playing on their teeth. If they did this no sound would come out.