Expansion with Class II AppliancesThe Herbst is oftentimes fabricated with an upper expansion screw. The traditional 12mm RPE screw typically provides enough expansion to balance out the lateral dimensions while the Herbst/MARA is worn.
MARA with expansion screws on both upper and lower arches.
Upper portion of a herbst appliance featuring an expansion screw.
Lower portion of herbst appliance featuring an expansion screw.