Functional Differences between Chewing Sides of Implant-Supported Denture Wearers

Humans are said to have habitual and non-habitual chewing sides; however, the functional differences between the chewing sides of implant-supported denture wearers have not been sufficiently clarified. This study aimed to clarify the presence or absence of functional differences between the chewing sides in implant-supported denture wearers. Forty-five patients with bilateral posterior implants were included in this study. The participants were asked to chew a gummy jelly on one side, and the masticatory movement was recorded using a Motion Visi-trainer (MVT V1). For 10 cycles from the fifth cycle after the start of mastication, the pattern of the movement path, the opening distance, the masticatory width, and the cycle time were calculated as parameters of masticatory movement. The amount of glucose eluted during the chewing of gummy jelly was measured and used as a parameter of masticatory performance. Each parameter representing masticatory movement and masticatory performance was compared between the right and left chewing sides and between the habitual and non-habitual chewing sides using a chi-squared test or a paired t-test. There was no difference in the frequency of masticatory path patterns between the right and left chewing sides. Most participants had a normal pattern on the habitual chewing side; however, abnormal patterns were also observed on the non-habitual chewing side. When comparing right and left chewing, no significant difference was observed between chewing sides in terms of opening distance, masticatory width, cycle time, or amount of glucose eluted (p > 0.05). When comparing the habitual and non-habitual chewing sides, masticatory movement on the habitual chewing side showed a larger opening distance (p < 0.001) and masticatory width (p = 0.008), shorter cycle time (p = 0.004), and higher masticatory performance (p < 0.001). It was suggested that there is a functional difference between the habitual and non-habitual chewing sides in the masticatory movement and masticatory performance of implant-supported denture wearers.