Class I - A malocclusion where the bite is okay and the top teeth line up with the bottom teeth, but the teeth are crooked, crowded or turned.

Class II - A malocclusion where the upper teeth stick out past the lower teeth commonly referred to as an "over bite," "over jet," "deep bite" or "buck teeth."

Overbite treatment with the Twin Block, 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.