Incisal changes and orthodontic stability.

Lateral cephalograms and study casts of 55 patients were evaluated to determine if any relationships exist among incisal positions and angulations, changes in positions and angulations, and long-term occlusal stability. No significant relationships could be found between long-term changes occurring in a number of commonly used incisal measurements and end-of-treatment incisal positions, changes in incisal positions during treatment, or long-term changes in the facial axis angle, ANB angle, or weighted PAR score. Long-term incisal changes occurring in individual patients were not necessarily associated with negative occlusal changes. Since incisal positions usually change in the long-term, it is suggested that the use of published norms or recommended absolute goals for end-of-treatment incisal positions be used more as general functional and esthetic clinical guides, rather than as predictors of stability.