Abstract
Purpose: Mandibular movement analyzing devices, which analyze the masticatory movement path, have come to be used for restoring mastication. In recent years, these devices have made it possible to conduct detailed analyses of the mandibular position around the terminal position of the masticatory movement path. However, the positional relation between the terminal position of masticatory movement and intercuspal position has not been sufficiently elucidated. Therefore, this study aimed to clarify the positional relation of the terminal position of masticatory movement to the intercuspal position, using a mandibular movement analyzing device and modified analysis software.
Methods: The subjects were five male dentists with healthy dentulous mandible. Using a mandibular movement analyzing device and software for analyzing the terminal position of masticatory movement, which was modified based on existing mandibular movement recording software, we analyzed the positional relation of the terminal position of masticatory movement to the intercuspal position. The test foods, which were cut into 10×10×10 mm sized pieces, included banana, kamaboko, apple, white bread, and French bread. The subjects were asked to perform mastication five times on each side of the mandible and repeated it twice (10 times), and each mandible movement was measured. Three-dimensional positions for the terminal position of masticatory movement were measured with the intercuspal position as a base point, for each test food in each subject.
Results: The terminal position of masticatory movement based on the intercuspal position was anteriorly or posteriorly located regardless of the test foods. For either different test foods or individual subjects, the maximum mean distance was only 0.18 mm. In regard to the positional relation of right and left, the maximum mean distance was 0.12 mm.
Conclusions: The results demonstrated that the terminal position of masticatory movement in healthy dentulous individuals is close to the intercuspal position.
