Class II malocclusion treatment efficiency with two-maxillary premolar extractions and with the First Class appliance anchored in mini-implants

• Ano de defesa: 2020
• Autor(a) principal: Tonello, Diego Luiz
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Anchorage; Ancoragem; Correção; Corrective; Extração dentária; Tooth extraction
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/25/25144/tde-22102021-154146/

Introduction: In this study, we compared the treatment time (TT) and efficiency of 2- maxillary-premolar-extraction protocols and First Class distalizer anchored in miniimplants (FCMI) in Class II malocclusion treatment. This study also compared in cases treated with 2-premolar extractions, whether there is difference when appointments are held once a month or at two-week intervals. Material and methods: A sample of 50 patients were divided into 3 groups, Group 1: treated with extraction of 2 maxillary premolars, 18 (eighteen) patients (10 male, 08 female), initial mean age of 14.38 ± 1.38 years and appointments monthly; Group 2: treated with FCMI, 13 (thirteen) patients (8 male, 5 female), initial mean age of 13.38 ± 1.31 years and Group 3: treated with extraction of 2 maxillary premolars; 19 (nineteen) patients (9 male, 10 female), initial mean age of 14.12 ± 1.38 years and appointments biweekly. The occlusal indexes Peer Assessment Rating (PAR) and the Objective Grading System (OGS) were used based on dental casts to calculate the percentage of occlusal improvement. In addition, was evaluated the TT, and treatment efficiency index (TEI). After verifying the normal distribution, the occlusal indexes, TT, and TEI the groups were compared with the t test (P<0.05). Results: Group 1 had a higher percentage of patients with complete class II than group 2 (66.7% and 15.4% respectively). TT in group 1 was 28.06 months, significantly less than group 2, which was 45.15 months. Group 1 was more efficient (TEI: 3.23) than group 2 (TEI: 1.95). Group 1 and group 3 presented significantly different TT (28.06 and 22.05 months, respectively); however, there was no difference in efficiency. Conclusion: Comparing group 1 versus group 2, final occlusal results were similar in both groups; however, the TT was significantly shorter in the extractions group, so it was more efficient. Now, when comparing patients treated with 2-maxillary premolars, the treatment time was significantly shorter in appointments every two weeks, but there was no difference in efficiency.