A STUDY OF MUSCLE MANIPULATION FOR OCCLUSION AND HEALTH

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 12470425
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 補綴理工系歯学
• Research Institution: TOKYO DENTAL COLLEGE
• Principal Investigator: SATO Toru TOKYO DENTAL COLLEGE, DEPARTMENT OF DENTISTRY, PROFESSOR, 歯学部, 教授 (50192092)
• Co-Investigator(Kenkyū-buntansha): AIHARA Kazuyuki TOKYO DENTAL COLLEGE,DEPARTMENT OF DENTISTRY, ASSISTANT, 歯学部, 助手 (70287176) ; YOSHIMURA Hirokazu TOKYO DENTAL COLLEGE,DEPARTMENT OF DENTISTRY, ASSISTANT, 歯学部, 助手 (60287191) ; KOSHIHARA Yoshimi TOKYO DENTAL COLLEGE.DEPARTMENT OF DENTISTRY, PROFESSOR, 歯学部, 名誉教授 (20085749) ; MIHO Otoaki TOKYO DENTAL COLLEGE, DEPARTMENT OF DENTISTRY, ASSISTANT, 歯学部, 助手 (60307395)
• Project Period (FY): 2000 – 2002
• Keywords: MUSCLE MANIPULATION / magnetoencephalograph (MEG) / mandibular movement / hearing loss / 顎運動障害

Research Abstract

Purpose of study
We have reported the clinical and epidemiological findings that hearing ability in hearing loss patients was improved by dental treatments including chewing instructions. The purpose of this study was to examine the effects of muscle manipulation on the mandibular movement and the auditory evoked magnetic fields (AEFs) response.
Materials and Methods
Subject: The mandibular movement and AEFs was recorded from healthy right-handed subject (fenjiale; age 36 years).The subject signed consent form approved by the Oral Health Science Center. The mandibular movement was measured by means of Gnatho HexagraphD (ONO SOKKI Co). The movement evaluated by the border movement and the habitual movement of the mandible. During the MEG recording, subject was sitting comfortably in a magnetically shielded room with the head supported in the helmet-shaped sensor array of the whole-scalp 306-channel magnetoencephalograph (MEG)(Vectorview^<TM>, Neuromag Ltd, Finland)
MEG measurement: Auditory stimulation was performed by tone bursts with 20-60 dB of 250 Hz. The duration of each stimulus was 40ms, and the interstimulus interval was 1 sec. The signals were band pass filtered (0.03-200Hz)and digitized at 600 Hz. The analysis periods of900ms included a prestimulus baseline of 100ms. About 200 responses were averaged for each condition. Overlaying the AEFs-profile and dipole fitting performed by 'Plotting' and 'Source Modeling' programs,respectively.
Healing ability: Healing ability was measured by Audiometer (Rion, AA97).
Manipulation of muscle and fascia: Manipulation of muscle and fascia associated with chewing performed for the subjectwith slight healing loss at 250Hz.
Results and discussion
The subject was aware of obvious improvement in hearing ability immediately after the manipulation, and also it was shown as 1 5dB increase at 250Hz by means ofaudiometer. In MEG measurement, it was shown that AErjs to sound stimuliwith 60 dB at 250Hz was increased by the manipulation. Same results were observed with 30dB and 40dB soundstimuli.
To evaluate the effect of muscle manipulation on mandibular movement, we compared the border and habitualmovements of mandible before and after manipulation. Improvements in the border and habitual movements of mandible were clearly observed by the manipulation.
Although prompt improvements ofthe hearing ability and mandible movement before and after muscle manipulation were shown in this study, it is unclear why the response ofAEF is enhanced by the muscle manipulation. The reasons ofthese improvements may due to increase bloodstream of cochlear and reduction of suppression by thei autonomic nerve system to the auditory cortex by the muscle manipulation.