What type of tooth movement typically requires a fixed appliance to achieve?

The movement of derotation typically requires a fixed appliance because it involves the precise alignment of a tooth that has rotated out of its ideal position. Fixed appliances, such as braces, are equipped with brackets and wires that apply continuous pressure to teeth, allowing for controlled movement. Derotation specifically focuses on correcting a tooth that has turned on its axis, which can be challenging to achieve with removable appliances that may allow for more movement and less control.

Other types of tooth movements, like correction of crossbite, distal movement along the arch, and reduction of overbite, can sometimes be addressed with removable appliances or functional devices, depending on the severity and specifics of the case. However, derotation generally necessitates the more stable and consistent forces provided by fixed appliances to ensure the tooth is rotated back into its correct orientation effectively. This level of control is essential for achieving the desired outcome in orthodontic treatment.