Effect of Altered Canine Guidance on Condylar Movement during Laterotrusion

Purpose: The purpose of this study was to investigate the effect of an altered inclination of the canine guidance on the pattern of the condylar movements during laterotrusion. Materials and Methods: The inclination of the canine guidance was steepened approximately 10 degrees by attaching a metal overlay to the lingual surface of the maxillary working-side canine. The laterotrusive movements of 20 young adults were measured using a three-dimensional mandibular movement analyzing system before and after alteration of the canine guidance. The difference between anterior, lateral, and inferior components of the working- and nonworking-side condylar movements, the Bennett angle, and the sagittal inclination of the nonworking-side condylar path before and after steepening of the canine guidance was evaluated by a paired t test. Results: After the canine guidance was steepened, the working-side condyle moved even more anteriorly and inferiorly. In contrast, little change was found in the direction and the amount of the nonworking-side condylar movement. Conclusion: The results of this study suggest that there is a relationship between the steepness of canine guidance and the pattern of the working-side condylar movement, but not between the steepness of the canine guidance and the pattern of the nonworking-side condylar movement.