Active Removable Appliances Arch Length Development-Sagittal The Sagittal appliances are designed to regain lost arch length in anterior and/or posterior direction.   Anterior Sagittal Upper & Lower To ensure anterior development, the design maximizes posterior anchorage with screw placement and occlusal indentations. click for larger view   Distal-Drive Upper & Lower This design facilitates distal driving of posterior teeth to regain lost arch length. To maximize distalization, splits are cut mesial to first molars. click for larger view     3-Screw Sagittal Upper & Lower This features the Sagittal design with a midline expansion screw for lateral development. click for larger view