Active Appliances


The sagittal appliance is probably one of the individually most used active appliances. Designed by Dr. Hermann Voss of Dortmund, Germany, there is no finer appliance to gain arch length. It can be designed for either anterior or posterior arch development.


In many class II cases the upper arch should be expanded independently prior to the use of a functional appliance.

The venerable "active plate" was designed by Dr. A.M. Schwarz, of Vienna. In wide use since the 1930s, it is still a very popular appliance for lateral arch development .


Often the inter-canine width is inadequate for the mandible to fit fully inside the upper arch. The fan gear will expand only the canines and bicuspids. The molar width will remain unchanged. This is especially useful in class II cases where a functional appliance is called for.


The RME is available in banded, bonded, or snap fit varieties. The ease of adjustment of the "Super Screw" is a definite advance in this time honored method of increasing arch dimension and can be used with any design.


The answer that practitioners have been seeking for years. Passive maxillary arch development that requires virtually no patient compliance. The nickel titanium alloy has a perfect memory. The expansion appliance will always return to the original dimensions with no adjustments.