Mandibular movement and EMG activity during ingestion and swallowing

We measured EMG activity in the cricopharyngeus during swaltowing in normal subjects using a newly-designed electrode. At the same time we measured motion ot the mandibte at the incisal point, and nose respiratory movements. We were able to define the onset ef EMG activity, though it was difficult to specity the end point because of low-frequency noise at the time of muscle relaxation. The onset of EMG activity preceded nasal respiration, which was arrested after closing. We concluded that because EMG actMty in the cricopharyngeus is extremely difficult to determine, it is better to evaluate it together with other parameters when evaluating swallowing activities. (J Osaka Dent Univ 2006 ; 40 : 1 --5)