Avaliação tridimensional das alterações no côndilo e na cavidade glenóide decorrentes do uso dos aparelhos funcionais Twin Block e de Herbst no tratamento das maloclusões de Classe II

Abstract

A 3D retrospective observational study and a 3D longitudinal retrospective pilot study constitute this thesis. The protocol was approved by the Ethics Committee (UERJ). The first study aimed to evaluate the alterations that occurred in the condyle (CO) and in the glenoid cavity (GC) resulting from the use of functional Twin Block (TB) and Herbst (HB) appliances in the treatment of class II malocclusions. The TB and HB groups had 12 patients (TB, 11.92 ± 1.08 years; HB, 12.5 ± 1.87 years). Cone-beam computed tomography (CBCT) scans were recorded before (T0) and after (T1) treatment (12 months). Complete three-dimensional (3D) models of T0 and T1 were superimposed in the Dolphin Imaging program. Partial 3D models of the CO and GC were segmented in the ITK-SNAP program. In the Geomagic Qualify program a coordinate system (axes X, Y and Z) was created in each 3D model T0 and then the CO and GC models were aligned in the 3D models T0 and T1. In each CO and GC a 3D centroid point was generated and evaluated between T0 and T1. Wilcoxon, Mann-Whitney and Spearman tests were used with 95% confidence. In the TB group, there was growth of the right CO (1.33mm) and, left CO (1.34mm), and of the right GC (0.80mm) and left GC (0.48mm) in a posterior direction. In the HB group there was growth of the right CO (1.43mm), and left CO (1.77mm), and of the right GC (0.12mm) and left GC (0.17) in a posterior direction. There was no difference in effects on CO and GC when TB and HB were used. The pilot study aimed to evaluate the changes in CO and GC resulting from the use of TB in the treatment of Class II malocclusions after one year of TB removal. In this study, 12 patients (11.92 ± 1.08 years) were evaluated using CBCT and were registered before (T0), during (T1: 12 months) and after (T2: 12 months) treatment. Full 3D models of T0, T1 and T2 were superimposed on Dolphin Imaging. Partial 3D models of the CO and GC were segmented in ITK-SNAP. In Geomagic Qualify a coordinate system (X, Y and Z axes) was created on each complete T0 and T1 3D models and then the CO and GC partial models were aligned. In each CO and CG, a 3D centroid point was generated and evaluated at T0 - T1, T0 - T2 and T1 - T2. Wilcoxon and Friedman multivariate tests were used with 95% confidence. In the periods T0 - T1 and T0 - T2, significant growth of right and left CO and GC, respectively, was found in the posterior direction. CO also grew significantly in the upward direction and GC in the downward direction, although not significantly. Patients who used TB had growth of the CO in a posterior and superior direction and of the GC in a posterior and inferior direction. The amount of CO growth was greater than the amount of GC growth