Change in EMG activity of the orbicularis oris muscle in relation to configuration of a plate within the labial vestibule during lip closure

Abstract

【Objectives】The aim of this study was to examine whether orbicularis oris muscle (OOM) activity during lip closure might be changed in relation to the thickness of a plate inserted into the labial vestibule (lip-plate)．

【Methods】Five normal adults participated in this study．Lip-plates were fabricated for each subject with a tailor-made basis in their width and height while the thickness of the lip-plate was adjusted as follows：5.0mm，7.5mm，10.0mm，12.5mm， 15.0mm and 17.5mm．Each subject was directed to keep the lips closed tightly with the lip-plate in place．Smoothed EMG signals of the upper and lower OOM were collected during lip closure．

【Results】OOM activity was correlated with changes in thickness of the lip-plate in place．The characteristics of changes in the activity were not different between the lower and upper lips．

【Conclusion】The OOM could be changed in accordance with the thickness of the lip-plate．It is suggested that lip function might be improved by means of a tailor-made lip-plate for person with dysphagia due to lip closing dysfunction．