Twin Block
The Twin Block is a removable functional appliance consisting of two bite blocks (twin blocks), upper and lower, that are designed to interlock at 70 degrees in such a manner that the mandible (lower jaw) is held in a more protrusive position. Over time, the repositioning of the lower jaw forward eliminates the overbite (horizontal projection of upper teeth beyond the lower teeth). When treatment with the Twin Block is complete, teeth in the upper and lower jaws will interact normally.

