Study of ingestion and swallowing using the gnathohexagraph

抄録

We evaluated ingestion and swallowing in healthy adults without somatognathic dysfunction using the Gnathohexagraph. The face bow of the Gnathohexagraph was Placeded on the mandibular anterior teeth and microphones were attached to the zygomatic bone and cricoid cartilage. The subjects were asked to ingest water and chew, jelly and fish cake(hereafter referred to as kamaboko)as common solid foods and barium containing jelly, hereafter referred to as Ba-jelly, as a test food. We observed jaw movements, muscle activities, occlusal sound and swallowing sound.
During water ingestion and swallowing, a clear occlusal sound and a short swallowing sound were recorded once following a shoot, simple mouth opening and closure. With jelly and Ba-jelly, several chewing cycles were observed, followed by two occlusal sounds and a short swallowing sound. With kamaboko, complex chewing cycle was observed, followed by a few occlusal sounds and a long swallowing sound of small amplitude.
We measured the time between the occlusal sound recorded at the end of chewing and occurrence of the swallowing sound(O-S lag). With water, the initial O-S lag was significant and had large variations that became somewhat stabilized after the fourth swallowing. Ingestion of kamaboko produced relatively stable results with a short O-S lag. Jelly and Ba-jelly produced larger O-S lags than kamaboko. The Ba-jelly produced a greater variation in results than did simple jelly.
We would like to increase the number of subjects in order to better understand normal swallowing and injection evaluation can be established for ingestion and swallowing disorder using Gnathohexagraph.