Tooth Vibration Research Articles

顎粘膜厚径の非侵襲的測定法の検討

Monitoring dynamical occlusal tooth contacts have a lot of significance and potentialities for clinical application.The purpose of this project was to establish the method for monitoring dynamical occlusal contacts by tooth vibration with miniature accelerometers attached on tooth surface.In this study, the evaluation on the accelerometer fixation method on tooth surface were conducted. A miniature accelerometer (MA 3: Morita, Co.) were examined on the vibration table with several kinds of fixation method and received the vibration caused by the random noise. The coherence, gain and phase of each obtained data were analyzed on Fast Fourier Transform (FFT) and compared.As the result, the most suitable fixation method of the accelerometer determined by the manipulation in clinical situations and in above mentioned factors was the one in which the resin core with and accelerometer bonded by cyanoacrylate bonding agent was fixed on the tooth surface by two-sided adhesive tape.

The delay time of tooth vibration signal recorded at facial skin surface.

The onset of a tooth vibration signal with a mini acceleration pickup attached to the skin on the forehead was delayed by 0.1788 ms on average after the actual tooth impact. When the signal was recorded at the zygomatic arch, the delay time was 0.1008 ms on average, which was significantly shorter than that obtained from the forehead (P less than 0.001). The difference due to a transposition of the vibrated tooth was also smaller (0.025 less than P less than 0.05) and had almost no effect on the intensities of the tooth flipping force. The delay time was even more prolonged when a poor frequency specification pickup and/or low pass filter were applied.

Response of Tooth to Transient Accelerative Vibration during Jaw Motions

Miniturized accelerometers were used to detect the tooth vibration during the motions of opening and closing jaws in this study. During recording procedure, accelerometers were retained with socket to the buccal surface of maxillary tooth. This method does not disturb normal mandibuler movements keeping natural tooth as it is.The purpose of this study was to develop practical use of this method in assessment of occlusion. Twenty-two male subjects were selected for this study, their age range was from 23to 34. Each subject possessed a full complement of tooth. They were subjected to (1) influence of head posture (Subject No.1), (2) value of acceleration response (No.2-6), (3) observation of occlusion and separation waves (No.7-16), (4) examination of uniatleral mastication (No.17-19), (5) synchronous records from effect of occlusion by inlay restration (No.20-22).From this observation the following summary can be obtained.(1) The “slight” change in head posture had little on the value of acceleration response.(2) Tooth transient vibration during jaw closing showed many vertical vibratory motions.(3) Propagation waves were obtained from anterior tooth during jaw closing, may be the determining factor on tooth contacts.(4) Basic components of separation waves were single impact, slide and combined forms.(5) Subjects of unilateral preference pattern of mastication on the first molar were proved many vertical vibratory motions in its side, and occlusal waves were short duration.(6) Synchronous records may be made of use in future studies.

A frequency analysis of tooth vibration during audible gnashing of teeth.

A frequency analysis of tooth vibration during audible gnashing of teeth.

Two types of motor pause in masticatory muscles.

Two types of motor pause in masticatory muscles.