Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 2 3 2005 09 15 86 90 M.S. A. Akhoundi M. Noori Sari F. Mojtahedzadeh 2015 10 03 Statement of Problem: Some vertical changes might be observed during the first stage of orthodontic treatment, aligning and leveling. Purpose: The aim of this study was to evaluate dental and/or skeletal vertical changes occurring in the first stage of preadjusted orthodontic treatment. Materials and Methods: Fourteen patients with an average age of 14.1 years were selected for this study. Preadjusted appliances were used and a lateral cephalogram was taken, subsequently. All patients were treated with four first premolar extractions. After 8 weeks of aligning and leveling, a second cephalogram was obtained. Results: No statistically significant changes including extrusion of all teeth except maxillary incisors were observed during this phase. Skeletal vertical changes also showed a slight non-significant decrease. Conclusion: The results of this study showed minimal vertical changes during the first stage of fixed orthodontic treatment with preadjusted appliances; therefore use of such appliances in patients with a tendency towards increased vertical dimensions could be justified. https://fid.tums.ac.ir/index.php/fid/article/view/58 https://fid.tums.ac.ir/index.php/fid/article/download/58/58