Early loss of the primary molars in an upper quadrant can lead to mesial eruption of the bicuspids and first molar. Because the anterior part of the arch is narrower, these teeth will often end up in crossbite. The mesial migration of these teeth also creates enough loss in the arch length that the cuspid either remains impacted or is forced to erupt labially from its normal position. To correct the crossbite and make room for the cuspid, the posterior segment needs to be moved distally and buccally. This Witzig Crossbite Appliance accomplishes this. In this design, the expansion screws are angled to provide a disto-buccal movement. The use of two screws is recommended to provide enough force to expedite crossbite correction. To clear the occlusion, the bite is opened with a posterior bite plane. The stationary side of the bite plane is usually ground into occlusion for extra stability while the moving side is left smooth. A cuspid retraction wire is often added to this appliance to begin guiding the cuspid back to its normal position.