Arch development appliances are designed to exert force to create space for crowded teeth and to help with widening or lengthening the arch. There are fixed and removable options and many different variations.
Removable appliances are more versatile because of the wide variety of design options available. They can be customized to perform different types of movement, for example in one or three directions, or only specific teeth with individual springs. It is also more hygienic because it can be removed from the mouth for cleaning. However, it does require patient compliance due to the fact it can be removed. The patient must commit to full-time wear to achieve and maintain movement.