STUDY ABOUT TISSUE CHARACTARIZATION ON MASTICATORY MUSCLES USING UTRASONOGRAPHY

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 09672119
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 矯正・小児・社会系歯学
• Research Institution: Showa University
• Principal Investigator: MAKI Koutaro DENTISTRY, SHOWA UNIVERSITY, LECTURER, 歯学部, 講師 (80219295)
• Co-Investigator(Kenkyū-buntansha): KUBODA Masato DENTISTRY, SHOWA UNIVERSITY, ASSISTANT, 歯学部, 助手 (30297030) ; NAKANO Haruhisa DENTISTRY, SHOWA UNIVERSITY, ASSISTANT, 歯学部, 助手 (80297035) ; SHIBASAKI Yoshinobu DENTISTRY, SHOWA UNIVERSITY, PROFESSOR, 歯学部, 教授 (40014005)
• Project Period (FY): 1997 – 1999
• Keywords: ULTRASONOGRAPHY / MASTICATORY MUSCLES / ECHO LEVEL / TISSUE CHARACTERIZATION / MUSCLE LOADING

Research Abstract

In order to investigate the muscle activity in masticatory muscles, we developed tissue characterization technique using ultrasonography.
Eleven subjects (12 to 32 years old) with craniomandibular deformities and four normal volunteers were studied. Muscle cross-sectional thickness and echo levels were evaluated in both side with ultrasound images. These measurements were carried out when biting, clenching and rest position. 7.5 MHz probe was used for real-time diagnostic examination. From the results, in normal subjects, thickness of masseter muscle increased at maximum biting and showed lower echo level in both side. However, in deformed subjects, left-right differences were observed in thickness and echo level. These findings suggested that the activity of masticatory muscles were evaluated by their changes of thickness and echo reflected value. The subjects with mandibular deformities demonstrated an imbalance in the biomechanical stresses during chewing not evident in the normal subjects. Quantitative and visible methods for evaluating the malfunctions have been needed for pre-clinical diagnosis and treatment planning. Our ultorasonographic diagnosticmethod described in this study proposed some kinds of solution, In this trial, malfunctions were visualized and evaluated clearly. In future, these diagnostic techniques will be used to derive a great deal of clinically useful information and to improve the combined evaluation of both static characteristics and dynamic function.