Jaw-closing muscles: electromyographic activity of human subjects with reduced periodontal support.

Summary The aim of this study was to compare the electromyographic (EMG) activity of jaw-closing muscles of individuals with normal and reduced periodontal bone support. Fourteen adult subjects with more than 24 remaining teeth and low levels of periodontal inflammation, were selected for the study. Subjects of the control group had 90% of the periodontal bone support left, while other subjects presented a reduction of 52% of the original periodontal bone. Chewing experiments were performed using silicone tablets, carrots and white bread. The EMG of masseter and anterior temporal muscles was performed bilaterally, using bipolar surface electrodes, and the EMG amplitude was full wave rectified, integrated and the area extension under the curve was used to access muscle activity. The results of the chewing experiments did not show any statistically significant difference in the EMG activity of the study groups, irrespective of the chewing stuff. The height of periodontal bone support did not seem to influence the electroactivity of jaw-closing muscles, indicating that reduced periodontal support might equally be able to withstand masticatory loads. Hence, individuals with reduced periodontal bone support revealed a similar EMG activity compared to subjects with normal periodontal bone support.