The effect of tongue position and resulting vertical dimension on masticatory muscle activity. A cross‐sectional study

Abstract

The purpose of this study was to: (a) compare the tonic electromyographic (EMG) activity of the temporalis and masseter muscles between two tongue positions, (b) compare the vertical dimension (VD) resulting from each tongue position and (c) determine the influence of the VD on the tonic EMG activity for each tongue position. Thirty-three healthy dental students with natural dentition and bilateral molar support, between the ages of 18 and 22 years, with no prior history of oro-facial injury, or current or past pain in the jaw, mouth, or tongue participated in the study. Tonic masseteric and temporalis EMG activities were recorded using surface electrodes. Subjects were instructed to passively place the tongue either on the anterior hard palate or in the floor of the mouth. At each tongue position, the resulting EMG and VD were recorded. No significant difference in EMG activity was found for either the masseter (P-value = 0·5376) or temporalis muscle (P-value = 0·7410), between the two tongue positions. However, there was a significant difference in the VD resulting from the two different tongue positions, being greater with the tongue placed in the floor of the mouth. There was no statistically significant correlation between VD and EMG activity for both tongue positions. In spite of the lack of difference in the effect of both tongue positions on the masseteric and temporalis EMG activity, an increment of the VD was registered for the floor of mouth-tongue position. However, VD was not correlated with EMG activity for both tongue positions.

Effect of tongue position on masseter and temporalis electromyographic activity during swallowing and maximal voluntary clenching: a cross‐sectional study

“…These results are in accordance with the study conducted by Valdés et al . . However, for the temporalis muscle, although the P ‐value was in the limit of statistical significance, there was less EMG activity when the tongue was in the FTP compared to the PTP.…”

“…Instead, Valdés et al . found no difference in the EMG activity of the masseter or temporalis muscles with either tongue position. However, the vertical dimension was greater with the tongue placed in the floor of the mouth.…”

“…In addition to recommending a specific resting tongue position as part of the treatment and management of TMD and oro‐facial pain , encouraging a specific tongue position during dynamic movements may also be helpful .…”

“…Several studies have attempted to define the therapeutic, correct or optimum conscious ‘resting’ tongue position that results in reduced masticatory muscle activity; however, there has been considerable controversy over this issue . Rocabado et al .…”

Influence of Myofunctional Therapy on Upper Intercanine Distance

“…An inverted rest posture of the tongue, resting on the palate, should therefore, contribute to a wider maxillary intercanine width [25].…”