Acurácia tridimensional do planejamento virtual em cirurgias ortognáticas

• Autor(a) principal: Teixeira, Andressa Otranto de Britto
• Data de Publicação: 2017
• 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/1/14070
• topic: Orthognathic surgery; Orthodontics; Imaging three-dimensional; Software validation; Computer aided design; Surgery computer-assisted; Cirurgia ortognática; Ortodontia; Imagem tridimensional; Validação de programas de computador; Projeto auxiliado por computador; Cirurgia assistida por computador; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA::ORTODONTIA

The success of orthognathic surgery depends on the surgical technique and on the accuracy of its planning. Planning in orthognathic surgery has evolved over the last two decades especially due to the development of three-dimensional virtual surgical planning. The objective of this study was to assess the accuracy of virtual surgical planning performed by the Dolphin Imaging© software through a three-dimensional methodology. The sample consisted of 10 individuals of both genders, after the growth period, with Class II or Class III malocclusions, requiring bimaxillary surgery and genioplasty. Those patients were followed up prospectively. The maxillofacial surgery staff of Pedro Ernesto University Hospital conducted all surgeries. Patient documentation consisted of preoperative cone beam computed tomography (CBCT), plaster models of upper and lower arches, photographs, and postoperative CBCT. The virtual planning were performed with the surgical module of the software. A prototyped interocclusal splint was used to transfer the digital planning to the real surgery. The accuracy was tested using the softwares ITK-Snap 3.6, Geomagic Qualify 2013© and MeshValmet 3.0. The difference between the virtual planning and actual surgery was calculated for the segments, using the root mean square (RMS) value of displacement of each individual fragment, and the translational displacements of the anatomical regions of interest (ROI) were measured through the three-dimensional displacement of the 3D centroid of each model. The data of the distances between surfaces considering RMS was analyzed by the Wilcoxon rank test. The data of differences between the centroids positions was calculated by the paired t-test and complemented by the Altman-Bland method and the Survival Agreement. The results showed that the distance between the surfaces were significantly different when considering the mandible position (p = 0.013) and the chin (p = 0.013). According to the position of the centroids it was found significant difference in the transverse direction of the right ramus (p = 0.034) when the direction of the displacement was taken into account and in the vertical direction of the right ramus (p = 0.005) and left ramus (p = 0.025) when the direction of the displacement was not considered. Considering a clinical relevance threshold of 2mm, it can be assumed that the segments of the maxilla, proximal (ramus) and distal (body) of the mandible were accurate, but the chin segment was not. It was concluded that the virtual surgical planning performed by the Dolphin Imaging© surgical module is accurate to determine the positioning of the maxilla, ramus and mandibular body segments, but can not be considered as having adequate accuracy for the positioning of the chin without the use of a specific positioner