[The stability of orthodontic treatment results]

A posttreatment evaluation of 72 patients, who are approximately 5.8 years out of retention, showed only little changes between the last appointment and the follow-up examination. The results can be considered stable. The statistic analysis indicated a correlation among some changes, which are important for treatment and therapy planning. For the stability in transversal and sagittal direction a maximal intercuspidation of the premolars and molars is as important as the exact positioning of the canines with lateral contacts in the dental arch. Transversal over-expansion should be avoided, because those results cannot be stabilized in the postretention period. The functional adaptation of muscles, the abolishment of habits and the duration of retention are essential preconditions for a stable treatment result.