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Abstract The purpose of this study was to evaluate the segmented arch technique in leveling deep curve of Spee. The sample of this study consisted of ten Class II division 1 female patients. The age of the sample cases ranged from 12-14 years. All the cases were indicated for treatment with extraction of the first premolars. For each patient orthodontic models, lateral cephalometric radiographas and intraoral photographs were taken before and immediately after the leveling stage. The main design of the appliance consisted of : 1 .Posterior anchorage unit. 2.Anterior unit. 3.An intrusive arch. The total intrusive force used was 160 grams (20 grams for each incisor and 40 grams for each canine). These forces are the Burstone’s recommended forces. On the basis of the results obtained from the present study, it was found that incisor intrusion was only one contributory factor to overbite reduction. Other factors included lower anterior teeth proclination and non significant molar extrusion. The average decrease in the overbite was about (3.43 mm.). The results of this study supported the hypothesis that, using sectional wires that include six elements (four incisors and two canines) displaces the center of resistance more distally. Distal center of resistance produces more control on the axial inclination of the intrusive unit. |