Denture mobility of complete dentures during function

Abstract

The purpose of this study was 1) to verify and apply a system to measure the three-dimensional (3-D) movement of the upper and lower complete dentures and the movement of the mandible with six degrees of freedom, and 2) to analyze the relationship between denture movements and the path of closure of the mandible during functions. A 3-D motion capture system with four infrared TV cameras was used for this purpose. The loci of each of three targets on the subject's head, the upper dentures, the lower dentures, and the mandible were measured three-dimensionally. The relationship between the lower dentures and the mandibular movements was analyzed in the change of the inner product of normal vectors of the denture occlusal planes and mandibular planes. The results were as follows: This system could measure the denture mobility within 3.5 x 10(- 1) mm in error. The mobility of the upper dentures had a correlation to the path of closure of the mandible regardless of the working side or nonworking side, and the lower dentures had a tendency to move toward the working side.