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The Scientific World Journal
Volume 2015, Article ID 690280, 5 pages
Clinical Study

Clinical Efficiency of Two Sequences of Orthodontic Wires to Correct Crowding of the Lower Anterior Teeth

1Ceuma University, Rua Josué Montello No. 1, Renascença II, 65075-120 São Luís, MA, Brazil
2FACIT Dental School, Rua D 25, Qd 11, Lt 10, Avenida José de Brito George Yunes, 77818-650 Araguaína, TO, Brazil

Received 31 March 2015; Revised 7 May 2015; Accepted 11 May 2015

Academic Editor: Grant McIntyre

Copyright © 2015 Cláudia Maria de Castro Serafim et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This study compared time to correction of mandibular anterior crowding using two arch wire sequences, one with conventional nickel-titanium (NiTi) arch wires and the other with conventional and NiTi heat-activated arch wires. Twenty-two boys and girls (mean age: 16.68 ± 2.66) with moderate crowding (3–6 mm) were assigned randomly to one of two groups and followed up for five months (six assessments) when arch wires were changed. Time to crowding correction was analyzed statistically using the Kaplan-Meier method. Data were collected during the five-month follow-up, and time to correction was compared between groups using the log rank test. At the end of follow-up, mandibular crowding was corrected in 100% of the cases in the group treated with the sequence that included NiTi heat-activated arch wires, whereas about 30% of those treated with NiTi arch wires were not completely corrected. There was a significant difference in time to complete treatment between groups (log rank = 5.996; ). In the group treated with the sequence that included heat-activated wires, alignment and leveling of mandibular anterior teeth were completed earlier than in the group treated only with conventional NiTi arch wires. Clinical trial registration is found at RBR-7g5zng.