These appliances are called BIONATORS. They are removable (disadvantage). They work to bring the lower jaw FORWARD and to push the upper jaw and teeth back. These are also called European Appliances since they are used a lot in "Europe". In America, they are quite popular and being used more and more by "Functional Orthodontists" who would rather NOT use headgear or extract. I follow this philosophy as much as possible, although when teeth have to be extracted, they gotta be extracted! Sometimes trying to be a hero can hurt the result.

Pictures

(click to enlarge)