This study compared in the sagittal plane the condylar positions determined by two methods for positioning the mandible into centric position. The observations were realized for thirty dentate subjects and the following methods were searched: unstrained hinging movement and inclination of the head backward. Rebased Temp-Bond wax records registered the mandible into centric relation occlusion position as determined by the studied methods. The maxillary and mandibular casts were mounted in a Whip Mix articulator and an instrument similar to the Buhnergraph was fixed to the articulator. With the casts related by means of the obtained centric records, styluses were depressed to mark points on recording tables positioned at the condylar level, on the right and left sides of the articulator. Changes of position in the points were measured with a profile projector (Nikon, model 6C, Japan). On the basis of the results and conditions of this study, the following conclusions were drawn: 1. All subjects of the sample showed the distance between the two points on the right side not equal to the one of the left side. However, the t test demonstrated no significant differences between the two sides; 2. The mean (standard deviation) for the distance between the two points of register was 0.54 (0.24) mm; 3. The unstrained hinging movement method showed higher degree of posterior condylar positioning over the inclination of the head backward method; 4. None of the studied methods showed a higher degree of superior condilar positioning.

Esta pesquisa comparou posicionamentos condilares no plano sagital de dois métodos de registro da relação central (RC): guiado não forçado (GNF) e inclinação da cabeça para trás (ICT). Os modelos superior e inferior de 30 indivíduos adultos, dentados naturais bimaxilares, foram montados em um articulador Whip Mix. Foi adaptado, na região das caixas condilares, um instrumento de registro semelhante a um Buhnergraph. Mordidas em cera refinadas com Temp-Bond, obtidas pelos métodos em estudo, orientaram a demarcação de pontos representativos dos posicionamentos condilares nos lados direito e esquerdo. As distâncias entre os pontos obtidos foram mensuradas com um projetor de perfil (Nikon, modelo 6C, Japão). Concluiu-se: 1. a distância entre os pontos de registro do lado direito não foi igual à do esquerdo, não sendo essa diferença estatisticamente significativa; 2. a média geral das distâncias entre os pontos de registro foi de 0,54 mm, com desvio padrão de 0,24 mm; 3. o método GNF demonstrou maior tendência em produzir posicionamentos condilares mais posteriores do que o método ICT; 4. em sentido infra-superior, não houve predomínio de um método sobre outro no sentido dos posicionamentos condilares.