Masticatory performance of unilateral chewing and free chewing.

This study aims to clarify whether there is a difference in masticatory performance between unilateral chewing and free chewing. The amount of glucose eluted was measured three times when 36 healthy dentate adults chewed gummy jelly for 20 s using two different chewing methods: unilateral chewing on the preferred chewing side and free chewing. The unilateral chewing cases were classified as group U (U1, U2, U3), and the free chewing cases were classified as group F (F1, F2, F3). In each group, the difference between the three measurements was investigated and inter-measurement reliability was assessed. The average of the three measured values and the difference between the largest and smallest values of the three measurements were calculated, and these were compared between group U and group F. The three measurements were similar in both groups U and F, and no significant differences were found between the measurements. Inter-measurement reliability (intraclass correlation coefficient, ICC) for group U was 0.956 for U1-U2-U3, 0.960 for U1-U2, 0.957 for U1-U3, and 0.952 for U2-U3. ICC for group F was 0.822 for F1-F2-F3, 0.832 for F1-F2, 0.871 for F1-F3, and 0.762 for F2-F3. The average of the three measured values was significantly greater in group U than in group F. The difference between the largest and smallest values of the three measurements was significantly greater in group F. These results suggested that there is a clear difference in masticatory performance between unilateral chewing and free chewing.