Uncovering the Herbst rods can make wearing the appliance more comfortable for some patients. On the other hand there can be some disadvantages to this procedure:

- it might make cementing or bonding of the appliance, in case of poor cooperation, impossible;

- it might interfere with vertical growth depending on the bearing points;

- it might disturb occlusion because of the wires that would pass over the occlusal surfaces;

- it might impair the retention of the appliance during the period when temporary teeth are being shed.

This article will also present other modifications, relating to the pivots, to the elimination of the anterior portion of the device, and to the use of springs on the branches. Their respective benefits and limitations will also be presented and discussed.