Pulsating forces in orthodontic treatment.

A controlled pulsating-force system for the orthodontic movement of teeth was designed and its biologic effects were examined, with the dog serving as an experimental model. This system was applied to the maxillary right second premolar while a continuous force was delivered to the maxillary left second premolar. After a 12-day experimental period in which pulsating forces were used, the amount of tooth movement and the radiographic and histologic changes were comparable to those produced by continuous force. These preliminary data indicate that forces of greater magnitude and duration will be necessary to more fully characterize the potential advantages of a pulsating orthodontic force.