The ethological analysis of stomatognathic function with 24 hours EMG of masticatory muscles

1991 Fiscal Year Final Research Report Summary

• Project/Area Number: 02454448
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 補綴理工系歯学
• Research Institution: Hiroshima University
• Principal Investigator: SATO Yuuji Hiroshima Univ. Sch. of Dentistry, Instructor, 歯学部, 助手 (70187251)
• Co-Investigator(Kenkyū-buntansha): OHKAWA Shuji Hiroshima Univ. Dental Hospital Assistant Professor, 歯学部附属病院, 講師 (90144865)
• Project Period (FY): 1990 – 1991
• Keywords: TM disorders / 24 hours EMG / CM dysfunction / Ethological analysis / Masticatory muscle activity

Research Abstract

The purpose of this study was to evaluate and compare ethologically the muscle activity between temporomandibular (TM) disorder subjects (TMD group) and normal subjects (N group). The subjects were 22 normal persons and 11 TM disorder persons. Electromyogram (EMG) was obtained from masseter muscle using bipolar AgAgCl surface electrodes and recorded on a portable cassette tape recorder for 24 hours. The behavior and meal menu of subjects were also recorded. The EMG recording was integrated, A-D converted and analyzed with our original analyzing programs on a personal computer. The 24 hours data was divided into 3 phases, i. e., meal time, sleeping time and the other time. TMD group and N group showed similar muscle activity patterns. However, in the meal time, the masseter muscle activity of the TMD group tended to be less than that of N group. On the other hand, in the sleeping time, the muscle activity of TMD group tended to be larger than that of N group. These results suggest a possibility to establish a new ethological diagnostic system of TM disorders and to find some potential patients with TM disorders in its early stages.