AIMThe purpose of this study is to compare the effects of the two clutches on recording the condylar movement.

METHODOLOGYTen subjects (6 women, 4 men; mean age 25.4 years) participated in the study. The mandibular movement, sagittal condylar inclination angle, and transversal condylar inclination angle of each subject were recorded with the CADIAX using the two clutches, respectively. The characteristics of the tracings of the protrusion, opening, and mediotrusion were analyzed with the t-test statistics at a = 0.05 level. The Kappa values were calculated for an assessment of the congruence of the tracings.

RESULTSThe results showed that the contour, direction, and dimension of the tracings in the two clutches were approximately same, but the tracings determined by the functional occlusal clutch were more regular and congruent. In the group segment recorded with the tray clutch, opening/closing paths of one subject showed crossed and time curves of three subjects appeared peak-like changes of velocity, but none were statistically different (P>0.05).

CONCLUSIONThe research suggests that the functional occlusal clutch should be preferred in the evaluation of the mandibular function, as the tracings with the tray clutch are more likely to produce false positive results.