Journal Article

Treatment times of Class II malocclusion: four premolar and non-extraction protocols

Guilherme Janson, Danilo Pinelli Valarelli, Fabrício Pinelli Valarelli and Marcos Roberto de Freitas

in The European Journal of Orthodontics

Published on behalf of European Orthodontics Society

Volume 34, issue 2, pages 182-187
Published in print April 2012 | ISSN: 0141-5387
Published online March 2011 | e-ISSN: 1460-2210 | DOI:
Treatment times of Class II malocclusion: four premolar and non-extraction protocols

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The purpose of this study was to retrospectively compare the treatment times of Class II division 1 malocclusion subjects treated with four first premolar extractions or a non-extraction protocol and fixed edgewise appliances. Eighty-four patients were selected and divided into two groups. Group 1, treated with four first premolar extractions, consisted of 48 patients (27 males and 21 females) with a mean age of 13.03 years and group 2, treated without extractions, consisted of 36 patients (18 males and 18 females) with a mean age of 13.13 years. Group 2 was subdivided into two subgroups, 2A consisting of 16 patients treated in one phase and 2B consisting of 20 patients treated in two phases. The initial and final Treatment Priority Index (TPI), initial ages, initial mandibular crowding, and treatment times of groups 1 and 2 were compared with t-tests. These variables were also compared between group 1 and the subgroups with analysis of variance followed by Tukey’s tests.

The treatment times for groups 1 and 2 and subgroups 2A and 2B were 2.36, 2.47, 2.25, and 2.64 years, respectively, which were not significantly different. Treatment times with non-extraction and four premolar extraction protocols are similar.

Journal Article.  3242 words. 

Subjects: Restorative Dentistry and Orthodontics

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