An alternative to a micro-screw for moving a tooth labially. With proper positioning and adjustment, this spring can also be used to correct minor rotations. To activate springs, simply pull forward on the spring’s arm with 139 Bird-Beak Pliers. Typically, if the lingual surface of the tooth to be moved is quite vertical, the acrylic is left over the top of the finger spring. However, if the lingual incline is rather shallow, it is suggested that a composite ledge be placed on the tooth's lingual.

A composite ledge will prevent the activated finger spring from riding up the lingual incline of the central -- and greatly improve its effectiveness. SML recommends that the acrylic be cleared away from the top of the spring. This makes it easier for the dentist to adjust the spring and easier for the patient to properly insert the activated appliance. Upon insertion, the patient needs to be certain that the spring arm “snaps” gingival to the composite ledge. Note: If any of the teeth are locked in lingual cross bite, it may be necessary to open the bite with an anterior or posterior bite plane.