Correlation between refractive error, muscle thickness, and bioelectrical activity of selected masticatory muscles.

The aim of this study was to analyze the correlation between the refractive error, muscle thickness, and the bioelectrical activity of selected masticatory and neck muscles in subjects with myopia. For bioelectrical activity analysis within the masticatory muscles, an 8-channel BioEMG III electromyograph was used. An M-Turbo ultrasound machine was used to analyze the masticatory and neck muscle thickness. Statistical analysis showed significant positive correlations between masseter muscle thickness at rest on the right side. Statistical analysis showed negative correlations between the digastric muscle and Activity Index within masticatory muscles at rest on the left side when the eyes were closed. As refractive error increases in myopic subjects, the resting tension on the temporal muscles increases, an increase in masseter muscle thickness is noted, and a decrease in bioelectrical activity on the digastric muscle at rest.