An orthodontic appliance includes a flexible vesica containing a fluid, and a support structure supporting the vesica relative to the patients dental anatomy. The support structure holds the vesica in compression against selected teeth, so that the fluid within the vesica exerts a therapeutic pressure on the teeth. For example, the support structure can include an arch-shaped trough to support a tubular vesica. The fluid can be an incompressible material, such as glycerin or water.
