How does the Herbst shorten the upper lip? This is a cartoon! No part of this video actually replicates what happens in real people. And who uses a Herbst in an adult patient? And how does a Herbst hold a whole lower jaw forward hanging off two (relatively) small upper molar teeth. Isn't it more likely that the much larger structure of the lower jaw, pushes the upper back teeth backwards... Rather than two little molar teeth pushing the (relatively) much bigger lower jaw forward? It's a simple matter of Newtonian physics... Equal & opposite reaction... Herbst appliances don't grow small lower jaws converting Class II to Class I... But they do hold back growth of the (otherwise normally sized) upper jaw... In children, not adults.
Come on Anatomage, use real cases to explain science, not cartoon imagination to explain absurdity.