Publisher: Shahid Beheshti University of Medical Sciecnes
Doi
Abstract
Introduction: Matching dental discrepancy (DD) with skeletal discrepancy (SD) in pre-surgical orthodontic preparation is crucial for obtaining a desirable surgical outcomes. The aim of the present study was to compare DD to SD in class III patients with and without extraction of the maxillary second premolars. Materials and Methods: This retrospective cohort study assessed subjects in two groups: the 1st group included individuals who were afflicted by class III skeletal and underwent non-extraction orthodontic treatment prior to the surgery; the 2nd group, included: patients who suffered from class III skeletal malocclusion and underwent tooth-extraction orthodontic treatment prior to the surgery. The Wits analysis was applied to establish the apical base relationship between the maxillary and the mandibular arches as measured along the Jacobson occlusal plane. Two angles were applied to determine the upper and lower incisors position to the skeletal base: IMPA (the lower incisor teeth to the mandibular plane) and the upper 1 to SN. The horizontal distance between the upper and lower incisors+2 mm was considered as the dental discrepancy. Results: Forty-six individuals were studied in the 1st group and 31 patients included in the 2nd group. The mean for DD was 7.39±3.40 mm in the 1st group and 9.65±2.57 mm in the 2nd group. The mean was 11.59±4.9 mm in group 1 and 8.48±2.35 mm in group 2. Pearson’s correlation did not show any significant correlation between dental discrepancy and the skeletal discrepancy in the 1st group (P˃0.05). A positive correlation was obtained between dental discrepancy and the skeletal discrepancy in the 2nd group (P˂0.001). Conclusion: It was magnificently attained that extraction of the second premolars of the maxilla could be a better match for DD and SD in the pre-surgical preparation in class III patients with an excessive SD
