Abstract
The tongue is a principal organ of the masticatory system that helps to prepare the food bolus with coordination of the teeth and mandible. Dynamic measurement method of the tongue shape was developed using an ultrasonic and CCD camera systems. The ultrasonic system consisted of a 3.5 MHz transducer whose beam scans the sector area of 90 degrees angle along the dorsum and the detector. To know the relative position of the probe to the head, markers attached to the probe and glasses detected using a CCD camera simultaneously during the ultrasonic measurement. Both signals of the ultrasonic and CCD camera were superimposed in an image signal using an audio-visual mixer and then the signal was digitized by a computer. The tongue and palatal shapes at a desired time were measured with image processing software after adjusting the movements of the head and probe.
The tongue shape to the palate was measured at the rest position of occlusion and at the time of increase of vertical dimension. The anterior portion of the tongue was coherent to the anterior palatal contour at the rest position. The tongue was often positioned to rear-downward at the time of increase of vertical dimension with the decrease of curvature of tongue.
