This fact is from Functional Appliances in Orthodontics. It is a commonly tested concept in NEET MDS examinations. Understanding this fact is crucial for answering MCQs correctly.
Twin Block = most popular functional appliance
Activator = Andresen = most studied
Frankel = vestibular shield = functional regulator
Herbst = fixed functional appliance
Jasper Jumper = flexible fixed functional
All work by mandibular advancement in Class II.