Centric slide in different Angle's classes of occlusion.

The purpose of this study was to test the possible differences in centric slide values between different Angle's classes of occlusion. The study included 98 participants divided into four groups: Angle's class I, Angle's class II, subdivision 1, Angle's class II, subdivision 2 and Angle's class III. All recordings were obtained using an ultrasound jaw tracking device with six degrees of freedom. The distance between the maximum intercuspation (reference position) and the centric occlusion was recorded at the condylar level. Anteroposterior, superoinferior and transversal distance of the centric slide were calculated for each participant, and the data were statistically analyzed (analysis of variance and Newman-Keuls post hoc test). No statistically significant difference was found in the anteroposterior and transversal distance of the centric slide between tested groups, while Angle's class II, subdivision 2 showed smaller vertical amount of the centric slide compared to Angle's class I and class II, subdivision 1. None of the 98 participants showed coincidence of centric occlusion and maximum intercuspation. Our results suggest that coincidence of the maximum intercuspation with the centric occlusion should not be expected. Smaller extent of the vertical distance of the centric slide could be morphological and a functional expression characteristic of the Angle's class II, subdivision 2.