1997 Fiscal Year Final Research Report Summary
Research of the Neurobiological and histological Changes of Periodontal Mechanoreceptors by Applying the Orthodontic Force
| Project/Area Number |
07672206
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
矯正・小児・社会系歯学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
KANEKO Tomoo Hokkaido Univ., School of Dent., Instructor, 歯学部, 助手 (10241340)
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| Co-Investigator(Kenkyū-buntansha) |
OKAZAKI Keiichiro Hokkaido Univ., School of Dent., Instructor, 歯学部, 助手 (20271687)
KAMATA Tsutomu Hokkaido Univ., School of Dent., Instructor, 歯学部, 助手 (20091431)
IMAI Tohru Hokkaido Univ., School of Dent., Assistant Professor, 歯学部, 助教授 (40160030)
AKAIKE Tadashi Hokkaido Univ., School of Dent., Professor, 歯学部, 教授 (70010105)
NAKAMURA Shinji Hokkaido Univ., School of Dent., Professor, 歯学部, 教授 (80001791)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Periodontal Sense / Periodontal Mechanoreceptors / Orthodontic Force / Inferior Alveolar Nerves / Trigeminal Main Sensory Nucleus / Tactile Sense and Pressure Sense / Immunohistology |
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| Research Abstract |
The purpose of this study was to investigate the response characteristics of periodontal mechanoreceptors after applying 100g orthodontic force with a closed-coil spring for either 1 day or 4 days. 28 cats were used in the experiment. We electrophysiologically recorded the responses of single periodontal mechanosentitive (Ms) units supplying the lower canine both from fine filaments dissected from the inferior alveolar nerves (Inf.) and from the trigeminal main sensory nucleus (Vms).
The responses of Ms showed two types of response pattern : slowly adapting type and rapidly adapting type. After applying the orthodontic force the ratio of the rapidly adapting type increased in Inf as well as in Vms. The thresholds and the latency of Ms in Inf.gradully increased after applying the orthodontic force. The thresholds of Vms.reachcd to a maximum after 1 day then decreased 4 days after applying the force. The latency remained unchanged.
On immunohistological research, we recognized the cell free zone in the pressure side of periodontium and the deformed nerves stained like a granule around there on 4 days after applying the orthodontic fcrce.
In the clinical examination 100g forces were applied to the upper central incisors of the 6 subjects (24-32years) by a lingual arch for 7 days. As a result, the thresholds of pressure sense were highest after 1 day and decreased after 7 days. But they were higher than control. The thresholds of tactile sense were highest after 2 days and decreased after 7days. This was also higher than control.
The results suggest that orthodontic force have effects on the response characteristics of periodontal mechanoreceptors. The cause of physiological changes incident to orthodontic tooth movement was probably due to tissue reorganization.
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Research Products
(2 results)
