Influência da alteração do plano oclusal: magnitude do movimento e tipo de osteossíntese na resistência mecânica da fixação na osteotomia sagital do ramo mandibular: estudo in vitro

• Ano de defesa: 2017
• Autor(a) principal: Santos, Victor Diniz Borborema dos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM SAÚDE COLETIVA
• Palavras-chave em Português: Osteotomia sagital do ramo mandibular; Técnicas de fixação da arcada osseodentária; Cirurgia ortognática; Avanço mandibular; CNPQ::CIENCIAS DA SAUDE::SAUDE COLETIVA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/24086

The aim of this study was to evaluate the resistance of fixation in the sagittal osteotomy of the mandibular ramus (OSRM) when performing great advances (12 mm), as well as the influence of the movement associated with the anticlockwise/clockwise rotation of the occlusal plane , Using plates and screws of the 2.0 mm system. Two types of advances were used (6 and 12 mm) using polyurethane hemimandibulars, with standardized OSRM, divided into 7 groups: G1 - linear advance of 6 mm / 1 plate and 4 screws; G2 - linear advance of 12 mm / 1 plate and 4 screws; G3 - linear advance of 12 mm / 2 plates and 8 screws; G4 - 12 mm advance, associated with clockwise rotation of the occlusal plane (15 °) / 1 plate and 4 screws; G5 - 12 mm advance, associated with clockwise rotation of the occlusal plane (15 °) / 2 plates and 8 screws; G6 - 12 mm advance, associated with anticlockwise rotation of the occlusal plane (15 °) / 1 plate and 4 screws; G7 - 12 mm advance, associated with the counterclockwise rotation of the plane (15 °) / 2 plates and 8 screws. The hemimandibules were submitted to a vertical compressive load in the first molar region and the applied force in Newtons was recorded in the displacements of 1mm, 5mm and 10mm, as well as the maximum force applied between 1 and 10mm. Using a 95% confidence interval, the means of strength were obtained and the groups were compared to each other. The statistical tests used were Kruskal-Wallis for the analysis of all groups and the Mann-Whitney test for comparison of two groups separately. The results showed that, according to the Kruskall-Wallis test, there were differences between groups. When only 1 plate was used for the fixation of the hemimandibula, at the 12 mm advance, the clockwise rotation was more resistant than in the linear movement, at the displacements of 1, 5 and 10 mm (p <0.05 **), Not resulting in statistical difference only in the maximum displacement (p = 0.112 **). In a large advance (12mm) there was a significant loss of resistance in the FIR, being necessary to compensate this situation with use of more fixation and the clockwise/counterclockwise rotation in these cases also added resistance in the OSRM, only in cases where a single plate is used. The counter-clockwise turn proved to be less sturdy than the clockwise rotation when fixed with one plate and more resistant when fixed with 2 plates. Both situations presented statistical significance with p <0.05. In view of these findings, it was concluded that regardless of movement, the fixation with 2 plates considerably increases the resistance to applied force.