The development of a device for condylar movement by electro-magnetic field. Part 1. Outline and characteristics of the device.
Akiko Nomura, Toyohiko Hayashi, Shuichi Nomura, Kiyoshi Ishioka, Yoshiaki Saitoh · Nihon Hotetsu Shika Gakkai Zasshi · 1990
It is very important for clinical diagnosis to record and analyze condylar movement in cranio-mandibular disorders. Recently, many devices have been developed for this purpose. These devices can measure precisely condylar movements, but are difficult to manipulate. We have developed a simple device which substitute a palpation of the posterior aspect of the TMJ. We modified the Cardiokymograph which use electro-magnetic field. The characteristics of this device are the use of a frequency-variable crystal-controlled oscillator, and the application of the coil itself which is a part of the oscillator as a probe. We tested many electrical characteristics of this device and assured the effectiveness, that is, sensitivity, directivity, frequency response characteristic, transient response characteristic, and temperature response characteristic. We tried to insert a probe into the external auditory meatus, and record condylar movement as a positional change of the skin. It seems to suggest that our device can record a feature of condylar movement.