Some morphological aspects of the meatus acusticus externus in connection with mandibular movements

A method is described to measure volumetric variations in the meatus acusticus externus caused by the movements of the mandible. Simultaneous registration of EMG activity and gnatho-sounds demonstrated that after tooth contact a slight decrease in volume, followed by some increase in volume takes place within 20-30 ms. The fast volume changes, during and after tooth contact, seem to be correlated to the speed of closure.