[A development of data analyzing system for the mandibular movement].

Recent developments in medical engineering has made it easy to record biological phenomena. Furthermore, the widespread popularity of the personal computer has made data processing system remarkably efficient. In this study, an efficient personal computer system for mandibular movement analysis is investigated, and a data analyzing system for that movement developed. Applying this system to chewing movements in a small number of cases made possible efficient, easy and accurate analysis. The following is an outline of the system and its applicability. 1. Standard measuring coordinate system for mandibular position and designation of mandibular position measuring point An orthogonal coordinate system is used to the standard measuring coordinate system for mandibular position measurement coordinates. The X axis of this orthogonal coordinate system is determined as a straight line connecting two LEDs. The origin point is designated as the center between two LEDs. This connects with the upper dentition or the maxilla. The mandibular position measuring point is designated on the orthogonal coordinate system. The X axis of this orthogonal coordinate system is determined as a straight line connecting two LEDs. The origin point is designated as the center between two LEDs. This connects with the lower dentition or the mandible. The analysis of mandibular position of designated measuring point on the lower dentition or the mandible is performed corresponding to the orthogonal coordinate system on the upper dentition or the maxilla. 2. Calculation of coordinates value [mm] for mandibular position measuring point In the analysis, value [V] for the distance between two LEDs established on the upper jaw is substituted for the already input real distance [mm] between two LEDs. The coordinates value of the mandibular position measuring point is calculated from these substitution value. 3. Data recording Data concerning mandibular movement and myoelectric discharges are recorded by means of a data recorder. Digital data are converted to analogue data from the data recorder by means of a 12-bit A/D converter and they are accumulated in the memory of the personal computer system. Digital data in the memory of the personal computer system can be stored in about 97 seconds for the storage capacity of a floppy disk (2HD) memory area.