Relationship between direction of tongue movement and palatoglossus muscle activity

Abstract

Purpose： It has not been clear whether the palatoglossus (PG) muscle might be involved in the digesting and/or swallowing function．The current study was aimed at electromyographically examining the relationship between direction of tongue movement and PG muscle activity．

Method： Four normal volunteers were used as subjects．Smoothed EMG signals of the PG muscle were collected．Each subject was instructed to perform four kinds of tasks as follows： 1）touching the angulus oris of the ipsilateral side of the electrode insertion site with the tongue apex； 2）touching the angulus oris of the contralateral side with the tongue apex； 3）protruding the tongue blade； and 4）raising the dorsum of the posterior tongue body to contact the palate．

Results： For all subjects，PG muscle activity was significantly greater for touching the tongue apex to angulus oris of ipsilateral side and for raising the dorsum of the tongue body than the other tasks．

Conclusion：The PG muscle might be involved in lateral movement of the tongue during the food processing stage by raising the ipsilateral side of the tongue when food is delivered and processed with the occlusal surface of the posterior teeth．