Abstract
The present investigation was undertaken to examine how the masticatory function is affected by an acute nasal obstruction. The nasal obstruction was administered by pinching the nose of each subject with a nose clip. We measured the chewing time and number of strokes, as well as the water content of the food bolus during the mastication of peanuts. In addition, the masticatory efficiency was also calculated using the mesh separation method. Under conditions of nasal obstruction, the chewing time lengthened significantly and the number of chewing strokes also increased compared to the control. In contrast to this, there were no significant differences between the water contents of the food bolus and the masticatory efficiency in the normal condition and the condition of nasal obstruction. When the chewing time was limited to that under the normal condition, all of the above mentioned parameters, such as the number of chewing strokes, the water content of food bolus and the masticatory efficiency, decreased significantly compared to those under the control condition. These results suggest that the prolonged chewing time under a condition of nasal obstruction may possibly be attributed to a compensatory action for getting an equivalent water content of the food bolus as under the normal conditions.
