Effects of oral screen exercise on orofacial and pharyngeal activity: An exploratory study using videofluoroscopy and surface electromyography in healthy adults.

OBJECTIVE: The oral screen is a device commonly used for treatment of orofacial disorders. The objective of this exploratory study was to examine the effect of oral screen exercise on the muscle activity in the lips, submental complex, masseter muscle, and kinematic activity of the tongue base, soft palate, pharynx, and larynx in healthy adults. This was compared with the kinematic activity during a dry swallow. It was hypothesized that not only the lip musculature but also other structures in the oral and pharyngeal cavities are activated while using an oral screen device.

METHOD: Ten healthy subjects used an oral screen during examination with videofluoroscopy and surface electromyography (EMG). Three different instructions for oral screen application and a dry swallow were examined.

RESULTS: The lip muscles showed the highest activity during oral screen exercise. The other muscle groups were activated to a lesser degree. The pattern of activation differed between individuals. Compared with a dry swallow, the range of motion of the tongue base, posterior pharyngeal wall, and the larynx was significantly smaller during oral screen activation. No major differences were found between three different instructions.

CONCLUSION: This study indicates that the lips and submental complex and, to a lesser degree, oral, pharyngeal, and laryngeal structures are activated with the oral screen, but the pattern of activation varied between individuals. In comparison to the activity during a dry swallow, range of motion during oral screen exercise is small.