| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
In clinical orthodontics, the position of the mandible is positively corrected when necessary. However, it still remains unknown whether the alteration of mandibular position exerts an influence on the whole body.
In this study, the shifting of gravity center with mandible at resting position, in occlusion and in clenching with voluntary occlusal force was measured to investigate whether or not the mechanism of physical adjustment, especially adjustment of equilibrium, was affected by the alteration of mandibular position. The following results were obtained.
1.In the testing with eyes closed, the distance and velocity of the shifting of gravity center tended to be relatively smaller, when the mandible was occluded, clenched with 10% occlusal force and clenched with 50% occlusal force than when the mandible was kept at resting position or clenched with 100% occlusal force.
2.The extent of shifting tended to be smaller except in one subject, when the mandible was occluded, clenched with 10% occlusal force and clenched with 50% occlusal force.
3.The center of gravity tended to be displaced on the whole toward the posterior direction.
4.Slight alteration of mandibular position at rest and in occlusion produced no signficant differences in the shifting of gravity center.
5.It seemed that clenching transmitted stimulation to clenching-associated jaw muscles, periodontium and temporomandibular joints, which in turn affected the mechanism of physical, especially somatic, adjustment to result in the shifting of gravity center which regulates the equilibrium function for the body.
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