[Stability of orthodontic correction: preconditions of relapses caused by occlusal forces].

The aim of the study was to determine the prognostic criteria of orthodontic treatment success in a group of patients with crowded teeth position and a neutral occlusion. The study included 150 patients (123 female and 27 male) with the average follow-up of 10.02±2.88 years and average retention phase of 6.15±2.98 years. Teeth positions, dental arches form, occlusal contacts and periodontal status were studied. Dentition changes after orthodontic correction should be considered as a result of adaptive compensatory balance. The resultant force acting on teeth and the direction of it determine displacement of teeth. The leading relapse precontidion induced by the occlusal forces was the interference of the canines, mandible deviation and asymmetry, muscle tone disorders.