1993 Fiscal Year Final Research Report Summary
A study on occlusal contact phase and the onset of the temporomandibular joint in para-functional mandibular movements
| Project/Area Number |
04671204
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
補綴理工系歯学
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| Research Institution | Aichi-Gakuin University |
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Principal Investigator |
TANAKA Kiyoo Aichi-Gakuin University, School of Dentistry, Head of Research Fellow, 歯学部, 助手 (70175446)
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| Co-Investigator(Kenkyū-buntansha) |
MACHINO Atushi Aichi-Gakuin University, School of Dentistry, Research Fellow, 歯学部, 助手
MORI Takashi Aichi-Gakuin University, School of Dentistry, Assistant Professor, 歯学部, 講師 (00159188)
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| Project Period (FY) |
1992 – 1993
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| Keywords | temporomandibular joint disorders / para-functional mandibular movement / occlusal contact / lateral excursion / protrusive excursion / 前方滑走運動 |
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| Research Abstract |
This study was to investigate the relationship between the onset of temporomandibular joint (TMJ) disorders and functional and para-functional mandibular movements, and their occlusal contacts on the location.
Noraml subjects were selected to examine the time for the onset of TMJ disorders, while maintaining their mandibular in functional and para-functional positions, and at the same time, we measured occlusal contacts on the location and it's area.
1. In lateral excursions, the distance from intercuspal position (IP) to the right canine edge-to-edge position (R2) was 3.9(〕SY.+-.〔)1.4 mm, and IP to the left canine edge-to-edge position (L2) was 3.7(〕SY.+-.〔)1.6 mm. The distance from IP to the right limit lateral excursive position (R4) was 10.1(〕SY.+-.〔)0.7 mm, and IP to the limit lateral left position (L4) as 10.5(〕SY.+-.〔)1.0 mm. In protrusive excursions, IP to the incisal edge-to-edge position (P2) was 3.2(〕SY.+-.〔)1.1 mm, and IP to limit protrusive position (P4) was 7.4(〕SY.+-.〔)0.5 mm.
2. The total number of occlusal contact points were as follows ; IP : 26.6(〕SY.+-.〔)8.9, P1 - P4 : 4.8(〕SY.+-.〔)4.2 - 2.4(〕SY.+-.〔)1.1, R1 - R4 : 8.2(〕SY.+-.〔)3.9 - 2.6(〕SY.+-.〔)2.1, L1 - L4 : 6.6(〕SY.+-.〔)4.6 - 1.0(〕SY.+-.〔)0.1.
3. The total amount of occlusal contact areas were as follows ; IP : 16.2(〕SY.+-.〔)9.0 mm^2, Pl - P4 : 2.4(〕SY.+-.〔)2.4 mm^2 - 1.2(〕SY.+-.〔)0.7 mm^2, R1 - R4 : 6.1 (〕SY.+-.〔)3.1 mm^2 - 1.9(〕SY.+-.〔)1.8 mm^2, L1 - L4 : 4.7(〕SY.+-.〔)3.7 mm^2 - 0.3(〕SY.+-.〔)0.2 mm^2.
No subject had TMJ disorders in the intercuspal position, but some subjects complained of TMJ disorders when the distance of lateral and protrusive movements were increased. Especially, over tooth edge-to-edge in lateral and protrusive mandibular position, more than 80% of the subjects complained of TMJ disorders.
It seems there were some relationships between the onset of TMJ disorders and para-functional mandibular movements and their occlusal contact phase.
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