Xinyi Ren1, Jiao Li1, Yunhe Zhao1, Houxuan Li2, Lang Lei1. 1. Department of Orthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China. 2. Department of Periodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China.
Abstract
OBJECTS: Appropriate torque expression contributes to ideal treatment outcomes both clinically and aesthetically. Whether active and passive self-ligating brackets (SLBs) have different torque-control capability in vivo has never been reported. The purpose of present study was to explore whether there was difference in torque expression in active and passive SLBs. SETTING AND SAMPLE POPULATION: In this retrospective study, 225 patients with four first premolar extraction were enrolled. For each patient, the digital lateral cephalometric radiographs were taken before and after treatment. METHODS: The study consisted of 2 groups: 111 subjects were treated with passive SLBs (Damon Q, Ormco) and 114 subjects with active SLBs (Empower 2, American Orthodonics). Measurements to determine skeletal changes and incisor inclination were obtained from cephalometric tracings using Dolphin software (Version 11.8, USA). Comparisons in both groups and intergroups were compared using t-tests and chi-square test. RESULTS: Significant differences in the variation of U1-SN(°), U1-NA(°), L1-NB(°) and L1-FH(°) were found between two groups. More labially inclined maxillary incisors were found in active SLBs group, while more labially inclined mandibular incisors were observed in passive SLBs group. CONCLUSIONS: With the present prescription set in the two brackets, active SLBs achieved more proclined maxillary incisors and retroclined mandibular incisors. Clinicians should take torque expression of brackets into consideration during orthodontic treatment. This article is protected by copyright. All rights reserved.
OBJECTS: Appropriate torque expression contributes to ideal treatment outcomes both clinically and aesthetically. Whether active and passive self-ligating brackets (SLBs) have different torque-control capability in vivo has never been reported. The purpose of present study was to explore whether there was difference in torque expression in active and passive SLBs. SETTING AND SAMPLE POPULATION: In this retrospective study, 225 patients with four first premolar extraction were enrolled. For each patient, the digital lateral cephalometric radiographs were taken before and after treatment. METHODS: The study consisted of 2 groups: 111 subjects were treated with passive SLBs (Damon Q, Ormco) and 114 subjects with active SLBs (Empower 2, American Orthodonics). Measurements to determine skeletal changes and incisor inclination were obtained from cephalometric tracings using Dolphin software (Version 11.8, USA). Comparisons in both groups and intergroups were compared using t-tests and chi-square test. RESULTS: Significant differences in the variation of U1-SN(°), U1-NA(°), L1-NB(°) and L1-FH(°) were found between two groups. More labially inclined maxillary incisors were found in active SLBs group, while more labially inclined mandibular incisors were observed in passive SLBs group. CONCLUSIONS: With the present prescription set in the two brackets, active SLBs achieved more proclined maxillary incisors and retroclined mandibular incisors. Clinicians should take torque expression of brackets into consideration during orthodontic treatment. This article is protected by copyright. All rights reserved.
Entities:
Keywords:
Fixed; Orthodontic Appliances; Orthodontic Brackets; Orthodontic Tooth Movement