Abstract
The purpose of this study was to analyze the mechanism of the disclusion of balancing-side teeth during mandibular lateral movement. Clinical examination was performed, and 59 normal young adults were divided into two groups, disclusion group and non-disclusion group. Lateral movements were measured with the six-degrees of freedom mandibular movement analyzing system, and the cuspla inclination was evaluated on the balancing-side second molars using a 3-dimensional digitizer.
In the frontal plane, the inclination of the working-side canine path was significantly smaller in the non-disclusion group than in the disclusion group, whereas there was no significant difference between the groups in the inclination of the balancing-side condylar path. There was significant difference in the cuspal inclination between the groups ; the cuspal inclination in the non-disclusion group was greater than that in the disclusion group. The results of this study suggest that the inclination of the anterior guidance plays an important role in the occurrence of the balancing-side disclusion during lateral movement, in comparison with the inclination of the posterior guidance, as well as in the occurrence of the posterior disclusion during protrusive movements.