Invisalign, an innovative invisible orthodontic appliance to correct malocclusions: advantages and limitations.

Tooth movement may be achieved by the use of sequential positioners made by altering tooth positions on set-up models to simulate progress of treatment. The principle is based upon Kesling's positioner concept of 1945, though its subsequent application to splint therapy was labour intensive and did not result in precise tooth movement. Invisalign was developed by Align Technology, Inc (Santa Clara, CA, USA) in 1997 by applying 3-D imaging technology to overcome these problems, and permitting customization on a large scale. Their system offers significant advantages, but still suffers from limitations which are discussed in this article.