Patent ID: 7156654

Claim:
A force adjusting mechanism for an orthodontic appliance located in association with a patient's dental arch and including spring means for applying force to one or more of the patient's teeth, the force adjusting mechanism comprising: a) a shaft operatively coupled at opposite ends between a first portion of the appliance which is anchored in the patient's dental arch and a second portion of the appliance including the spring means which applies force to one or more of the patient's teeth; b) a lock movable along the shaft to compress the spring between the lock and the second portion of the appliance; and c) co-operating structures on the shaft and on the lock to provide a unidirectional ratchet movement of the lock along the shaft; d) so that the lock may be advanced one step at a time in one direction only to compress the spring to apply force in a stepwise manner to one or more of the patient's teeth.