Comparison of direct skeletally anchorage distalization and two premolar extractions for Class II treatment

• Autor(a) principal: Ciantelli, Thales Lippi
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://www.teses.usp.br/teses/disponiveis/25/25144/tde-25112021-115622/
• topic: Angle Class II; Imageamento tridimensional; Imaging; Má Oclusão de Angle Classe II, Procedimentos de ancoragem ortodôntica; Malocclusion; Orthodontic anchorage procedures.; Three-dimensional

Introduction: to compare the dentoskeletal and soft-tissue effects of Class II malocclusion treatment using two different protocols: maxillary premolar extractions and skeletally anchored molar distalization using the Miniscrew-Anchored Distalizer with lateral radiographs and digitized models. Material and Methods: The sample comprised 35 patients with Class II malocclusion divided into two groups: Group 1 consisted of 15 patients treated with the Miniscrew-Anchored Distalizer (MAD), followed by fixed appliances. Group 2 consisted of 20 patients treated with maxillary first premolar extractions (XP2). Lateral radiographs were digitized with the ScanMaker i800 and analyzed with the Dolphin Imaging 11.9 software. The plaster models were digitized with the scanner 3Shape R700 and the digitized models were analyzed with the software OrthoAnalyzer. The intergroups treatment changes were compared with t-tests or Mann-Whitney tests, depending on normality. Results: The MAD group presented significantly greater intrusion of maxillary incisors, maxillary molar distalization and distal rotation, mandibular incisors labial tipping and mandibular molars mesialization. The XP2 group showed significantly maxillary molar mesial movement, greater reduction in the intermolar distance, arc perimeter, and arc length. Conclusion: Both protocols effectively treated Class II malocclusion promoting dentoalveolar changes. The MAD produced more mandibular incisor\'s labial tipping and accentuated molar distal rotation. The XP2 protocol promotes significantly greater reduction of the transversal arch dimensions.