M624: Temporary Anchorage Devices: Indications and Applications

Abstract

It should be self-evident that good diagnosis and treatment planning are vital in providing a favorable orthodontic outcome. Anchorage management is an integral part of that process. Anchorage, the resistance to unwanted tooth movement, determines the limits of desired tooth movement possible and accordingly the amount of correction possible. Traditionally, anchorage strategies for maximum tooth movement were largely dependent on patient compliance. Intraoral and extraoral auxiliaries were used in addition to grouping multiple teeth and pitting them against few. Over the last two decades, there has been increasing interest in establishing absolute anchorage with implantable devices which respond like ankylosed teeth. Although interest in this approach has grown dramatically in the last decade, the notion is not new. In their 1945 paper, Gainsforth and Higley reported the concept of basal bone anchorage via orthopedic bone screws placed in the mandibular ramus. Currently, although a multitude of vendors proffer a confounding variety of devices, there are only four basic approaches to implantable anchorage. These involve the use of osseointegrated implants, modified bone screws, modified bone plates and special purpose midpalatal implants. In the mutilated dentition, osseointegrated implants provide excellent anchorage and with the appropriate planning and placement, can subsequently be incorporated into the final prosthetic treatment. The remaining three categories are intended to be temporary and are removed at the conclusion of active use.