When the distance of the interincisor opening was increased, the canine was gradually loaded, but the load on the first and second premolars decreased using the TheraBite^® appliance.
Conversely, as the distance of the interincisor opening increased, the canine and the first and second premolars were loaded gradually in the shell-shaped mouth opening appliance.
Additionally, the central and lateral incisors were loaded at all times in the shell-shaped mouth opening appliance.