Analysis of head and mandibular posture and tongue shape by the timesharing magnetic sensor with six degree of freedom in rest and spontaneous swallowing

四个磁性传感器安装在下切牙部分、头部和右肩和左肩。舌形传感器是由五片双压电薄膜串联而成，传感器粘贴在舌面上。利用该传感器在自然吞咽状态下获得了舌形变化产生的电压。这些方法能够获得头部、下颌和上半身的姿势信息，以及三维空间中的舌形信息，事先向参与实验的受试者解释实验内容，并同意本研究的配合。受试者由正常咬合病例和开牙合病例组成。测量头部、下颌和上半身的姿势变化，分别为静息姿势和自愿吞咽姿势。此外，舌形的测量是在自发吞咽…上完成的1)利用三维计算机图形学实时观察受试者的下颌轨迹。2)开牙合病例的头部姿势有向上倾斜的趋势，以便在静止时转为正常咬合病例。1例开牙合病例的上半身未出现典型的倾向性。在自发性吞咽时，正常咬合病例的头部姿势与下颌姿势的运动同步变化，并有与上半身相似的趋势，但姿势变化较小。在开牙合病例中，下颌的姿势变化与头上体的姿势变化的同步性不明显。3)在正常咬合情况下，舌背向下的位置在舌尖到达最高位置之前就开始向下，在舌尖达到最高位置后，舌背向下的位置最低。在开牙合病例中，背部向下的开始时间与正常咬合病例相似。从上述结果推测，代偿性舌运动是为了维持吞咽负压而发生的，这种代偿性舌动适应于前张开牙合。较少

Four magnetic sensors were attached on lower incisor part, a head, and a right and left shoulder. The sensor for tongue shape was constructed five bimorph piezoelectric films which were arranged to the series, and those sensor was bonded to the surface of tongue. The voltage generated by the tongue shape change was obtained with this sensor at spontaneous swallowing. These methods were enabled to obtain the postural information of the head, mandible and the upper body, and the shape information of the tongue in three-dimensional space.The subjects who had participated in this study were explained the content of the experiment beforehand, and consented to the cooperation of this study. These subjects were composed of the normal occlusion case and the openbite case. The measurements of the postural changes for the head, mandible and the upper body were at a rest position and a voluntary swallowing. In addition, the measurements of the tongue shape were achieved at spontaneous deglutition … More .1) The mandibular tracking of subjects was in observed by using three dimensional computer graphics in real time.2) The head posture of an openbite case had a tendency that the head inclined to up for the postural change to a normal occlusion case at the rest. The upper body of an openbite case did not show the characteristic tendency. In spontaneous swallowing, the head posture of a normal occlusion case showed the postural change synchronizing with the movement of mandibular posture, and a tendency similar as for the upper body was recognized, but the postural change was a little. In an openbite case, the synchronization of the postural change of mandible and the postural change of the head and upper body was not clear.3) In normal occlusion case, the downward in the dorsum of tongue had started before the tongue tip reached an uppermost position, and after the tongue tip reached an uppermost position, the dorsum of tongue was located most downward. In openbite case, the beginning time of the dorsum's downward was similar to the normal occlusion case. From the above-mentioned result, it was guessed that the compensatory tongue movement, which had been adapted to anterior openbite, occurred to maintain a negative air pressure for swallowing. Less