Relation Between Occlusal Parameters and EMG Activity With/Without Visual Feedback

Objectives: In occlusal adjustment, patients are asked to vary their bite force to confirm contact. However, individual interpretations of 'light' and 'heavy' bites differ. This study aimed to use sEMG with visual feedback for varying bite force, followed by computer-assisted occlusal parameter evaluation. This study explored the feasibility of applying sEMG with visual feedback.
Methods: Twenty four healthy participants, 12 men and 12 women, were enrolled in this study. The study was to explore the acquired data from DPS II while monitoring the surface EMG activities (Teethan® , MI, Italy) of bilateral masseter muscles under different tasks, including objective visual feedback tasks (70%, 35%) and subjective heavy and light force tasks. The muscle activities/bite force ratio and measured data from DPS II of each task was calculated. Linear regression and Wilcoxon singed-rank tests were used for statistical analysis (SPSS software version 25). The significance level was set at .05.
Results: 1. No significant gender or preferred side differences was found in the muscle activity/bite force ratio. All bite force-EMG relationships displayed a strong positive correlation, indicating that higher EMG activities correlated with greater bite force.
2. Visual feedback instructions revealed significant differences between 70% and 35% instructions, while preferred and non-preferred sides showed no significant differences. Similarly, heavy and light force instructions led to significant differences in measured data, with no variations between preferred and non-preferred sides.
Conclusions: 1. The bite force-EMG relation exhibited a strong positive linear correlation in all subjects.
2. The muscle activity/bite force ratio showed no significant differences, regardless of gender or preferred side.
3. Monitoring bilateral masseter muscle sEMG activities allowed participants to observe significant differences in the measured data during heavy and light force tasks under visual feedback.