Alterações dentoesqueléticas associadas aos aparelhos Twin Block e Herbst com e sem ancoragem esquelética no tratamento da má oclusão Classe II: um ensaio clínico randomizado

• Autor(a) principal: Palomares, Nathália Barbosa
• Data de Publicação: 2019
• Outros Autores: [e-mail]
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/17258
• topic: Malocclusion, Angle Class II; Functional appliances; Craniofacial growth; Cone-Beam Computed Tomography; Facial bones - Growth and development; Maxillofacial development; Orthodontic appliances; Má oclusão de Angle Classe II; Aparelhos propulsores mandibulares; Crescimento craniofacial; Tomografia computadorizada de feixe cônico; Ossos faciais - Crescimento e desenvolvimento; Desenvolvimento Maxilofacial; Aparelhos ortodônticos; CIENCIAS DA SAUDE::ODONTOLOGIA::ORTODONTIA

The aim of this randomized controlled trial was to compare the dentoskeletal effects associated to the treatment of Angle Class II 1st division with removable, fixed and skeletal anchored functional appliances. After the clinical examination of 1039 individuals, 34 patients with Angle Class II, 1st Division, overjet ≥ 6 mm, 10 to 14 years old, at the peak of the pubertal growth spurt and no history of orthodontic treatment were included. These patients were randomized into three groups: (TB) treated with removable Twin Block appliance (n = 13); (HAD) treated with fixed cemented Herbst appliance (n = 11); and (HAE) treated with Herbst appliance associated to two mandibular mini implants (n = 10). Cone-beam CT scans were obtained before (T1) and after 12 months of treatment (T2). In the ITK-SNAP® software, 3D models of the maxilla, mandible, central incisors and 1st molars were built. In the Dolphin Imaging® software, full 3D models of T1 and T2 hard tissue were generated, with standardized head orientation and registration in the anterior cranial base. The Coordinate Transfer Model (CTM) was obtained from the T1 soft tissue, with standardized slices in the axial, sagittal and coronal planes. In the Geomagic Qualify® software, the partial 3D models were aligned to the spatial position of the oriented and registered full 3D models. An automatic method was used to determine centroid points, which represented the spatial position of all evaluated anatomical structures. Centroid displacements between T1 and T2 were analyzed using the Cartesian coordinate system based on the CTM. The cranial register was used to analyze the growth of maxilla and chin; to measure tooth movement and condylar growth, the regional register in the maxilla and mandible were adopted. The Wilcoxon test assessed intra-group differences and the Kruskal Wallis test analyzed intergroup differences in skeletal and dental changes. Success rates for overjet correction and molar relationship were compared. Anteroposterior maxillary growth restriction was detected (HAE: -0.26 ± 2.88 mm; TB -0.25 ± 0.66 mm; HAD: 0.18 ± 0.87 mm) and also anteroposterior mandibular growth (HAE: 4.21 ± 2.96 mm; HAD: 3.49 ± 3.74 mm; TB: 1.24 ± 3.36 mm). In the upper arch, minimal movement of incisors and 1st molars was observed (≤ 1 mm in the 3 planes). The main dental effects occurred in the lower arch, in the anchorage loss (HAD: 1.73 ± 0.64 mm; TB: 1.45 ± 1.13 mm; HAE: 1.07 ± 0.23 mm) and minimal projection of central incisors (HAE: 0.93 ± 0.08 mm; HAD: 0.54 ± 0.36 mm; TB: 0.27 ± 0.18 mm). The highest overjet correction was obtained by the HAD (-4 ± 1.65 mm) and HAE (-4 ± 1.47 mm) groups, followed by TB (-3 ± 3.25 mm). In the molar relationship, the highest efficacy was in the HAE group (100% successful, 85.7% overcorrected), followed by HAD (100% successful, 70% overcorrected), and TB (55.6% successful). It was concluded that the Herbst appliance associated with mini-implants had greater efficacy in predominantly skeletal correction of Class II 1st division malocclusion than the Herbst and Twin Block appliances after 12 months of treatment.