Plural points analysis on condylar movements under the altered anterior guidance

Abstract

It is important to consider the relationship between tooth guidance and condylar movements from the point of view of occlusal reconstruction and analysis of the physiological relationship between stomatognathic function and occlusion. We examined the movements of working and balancing side condyles during lateral excursions, when the anterior guidance was altered but without changing the intercuspal position. When the incisal path angle became steeper than the natural tooth guidance angle, the distance of the balancing side condyle paths (center of the condyle paths) decreased significantly, whereas the distance of the working side condyle paths (center of the condyle pathways) remained unchanged. The trajectories of the working side condyle paths were found to be random, whereas those of the balancing side condyle paths remained stable. The analysis of six points around the center of the condyle indicated that the working side condyle paths were affected passively following an alteration in the tooth guidance angle and that the balancing side condyle performed an active role during lateral excursions.