Which appliance serves as a fixed palatal anchorage device connected to the upper molars to resist mesial movement?

Which appliance serves as a fixed palatal anchorage device connected to the upper molars to resist mesial movement?

• A. Hawley Retainer
• B. Hyrax Expander
• C. Nance Appliance
• D. Schwarz Appliance

Answer: (C)

Anchorage in the upper arch is achieved with devices that provide a fixed counterforce to prevent the back teeth from moving forward. The Nance appliance does this most directly: it is connected to the upper first molars with bands and features an acrylic shield that sits against the palate. That shield acts as a physical barrier and resistance point, so the molars are less prone to mesial drift while other tooth movements are occurring. Because it is fixed and palatal, it provides a stable anchor for the posterior segment. The other options serve different primary purposes. A Hawley retainer is typically removable, offering some retention and minor anchorage but not a fixed palatal anchor. A Hyrax expander is a fixed appliance aimed at widening the palate via a screw, so its main job is expansion rather than resisting mesial movement of the molars, even though it is attached to them. The Schwarz appliance is another expansion-type device and is not the standard fixed palatal anchor used specifically to prevent mesial drift of the upper molars. So, the Nance appliance best fits the role of a fixed palatal anchorage device connected to the upper molars to resist mesial movement.

Anchorage in the upper arch is achieved with devices that provide a fixed counterforce to prevent the back teeth from moving forward. The Nance appliance does this most directly: it is connected to the upper first molars with bands and features an acrylic shield that sits against the palate. That shield acts as a physical barrier and resistance point, so the molars are less prone to mesial drift while other tooth movements are occurring. Because it is fixed and palatal, it provides a stable anchor for the posterior segment.

The other options serve different primary purposes. A Hawley retainer is typically removable, offering some retention and minor anchorage but not a fixed palatal anchor. A Hyrax expander is a fixed appliance aimed at widening the palate via a screw, so its main job is expansion rather than resisting mesial movement of the molars, even though it is attached to them. The Schwarz appliance is another expansion-type device and is not the standard fixed palatal anchor used specifically to prevent mesial drift of the upper molars.

So, the Nance appliance best fits the role of a fixed palatal anchorage device connected to the upper molars to resist mesial movement.