1991 Fiscal Year Final Research Report Summary
Examination and diagnosis of bruxism and occlusal trauma in periodontitis patients
| Project/Area Number |
02454432
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Conservative dentistry
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| Research Institution | Hokkaido University |
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Principal Investigator |
KATO Hiroshi Hokkaido Univ., Dental School, Professor, 歯学部, 教授 (60001020)
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| Co-Investigator(Kenkyū-buntansha) |
IWANAMI Tomotoshi Hokkaido Univ., Dental School, Instructor, 歯学部, 助手 (70184893)
SAKAGAMI Ryuji Hokkaido Univ., Dental School, Instructor, 歯学部, 助手 (50215612)
HONGO Okito Hokkaido Univ., Dental School, Lecturer, 歯学部附属病院, 講師 (80199562)
TSUKUBA Nobukazu Hokkaido Univ., Dental School, Lecturer, 歯学部附属病院, 講師 (10155351)
KAWANAMI Masamitsu Hokkaido Univ., Dental School, Ass. Professor, 歯学部, 助教授 (10133761)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Bruxism / Periodontitis / Occlusal trauma / Premature contact / K-6 diagnostic system / EMG / Jow movement / T Scan system |
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| Research Abstract |
This study was undertaken to clarify the actual conditions of the bruxism in periodontitis patients, occlusal traumatism, and periodontal destructions. Following findings were obtained.
1. Monitoring mandibular movement and muscle activities of moderate to severe periodontitis patients with K-6 diagnostic system revealed that periodontitis patients showed : 1) slower contact velocity in mouth closure ; 2) lower electromyogram activity in firm biting ; . 3) decreased electromyogram activities as periodontitis progressed and occluding site decreased.
2. A device for monitoring jaw movement during sleep was made. Jaw movement, masseter activity, occluding contacts, occluding sound were recorded and analyzed. Bruxism was classified into three types : A type (grinding), B type (clenching), and C type (except A and B). Subjects with consciousness of bruxism had more A type, and subjects without consciousness had more B type. These difference seemed to contribute to the awareness of their bruxism.
3. The self recording device for monitoring bruxism during sleep was improved by disposal electrode and illuminated diode monitor, and they made the measurement more accurate.
4. Periodontal destruction combined with occlusal traumatism and inflammation was studied. Two macaca monkies were used and molar area were divided into four groups. After 14 and 28 weeks, clinical and pathological observations were performed. The result showed when inflammatory cells were infiltrated in trans-septal fibers, the destruction spread rapidly into apical site with occlusal traumatism.
5. For examining premature contacts which cause bruxism, T-scan system was used for periodontitis patients. The observations revealed that this system is not accurate enough for periodontitis poitients examinations because of patients instability of occlusion, teeth mobility and weekened occlusal force.
We are planning to have further research for the objective diagnosis and treatment modalities for bruxism.
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