Begg-edgewise diagnosis-determined totally individualized orthodontic technique: foundations, description, and rationale

Abstract

This article presents an appliance system designed to facilitate efficient treatment by the use of the biomechanical approach considered most suitable by the orthodontist for the individual patient. The system described uses narrow, single brackets with 0.022 X 0.028 inch edgewise arch wire slots and 0.020 X 0.020 inch vertical slots for various auxiliaries. There are five brackets that differ only in the torque of the arch wire slot-0 degree, 5 degrees, 10 degrees, 15 degrees, and 20 degrees. Thus, an appropriate bracket can be selected for any tooth in any situation. The brackets and bonding pads are small in all dimensions to ensure optimal appearance and interbracket arch wire spans and minimal lip and cheek irritation. This also lessens occlusal interference, enamel surface involved in bonding, and problems with gingival proximity and oral hygiene. The basic buccal tubes are conventional 4.5 mm long, 0.022 X 0.028 inch torqued edgewise tubes. A buccal tube assembly with a similar additional rectangular tube carried diagonally at a 15 degree angle across the buccal surface of the basic tube (its mesial end pointing gingivally) is used in extraction cases with deep overbites or moderate-to-severe anchorage requirements. The angulated outer tube carries the main (working) arch wire during the bite-opening and retraction phases of treatment. A rectangular sectional wire in the inner tube and second premolar bracket locks the molar and premolar teeth together so that neither can tip independently. As a unit they provide anchorage for bite opening and retraction. The gingivally positioned and angulated outer tube directs the arch wire out of danger of distortion from mastication and provides a built-in biteopening effect. The molar and premolar teeth, in effect, become a single large tooth with its center of resistance (CR) further mesial than the CR of the molar. Sectional wires result in a more favorable system of moments created by arch wires and elastics. This delivers more intrusive force to the incisors with less tendency to tip the anchor units. The appliance provides the orthodontist with an extensive range of options in treatment mechanics--from anchorage conservation and rapid movement of limited tipping by light forces to translation or stabilization with precise three-dimensional control.