Impact Velocities of the Teeth after a Sudden Unloading at Various Initial Bite Forces, Degrees of Mouth Opening, and Distances of Travel
| Autor: | Geranda Slager, Tadashi Nagashima, Egbert Otten, M.L. Broekhuijsen, J.D. van Willigen |
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| Rok vydání: | 1997 |
| Předmět: |
Dental Stress Analysis
Dentistry Statistics Nonparametric 050105 experimental psychology Bite Force 03 medical and health sciences 0302 clinical medicine Impact velocity Neural control Humans 0501 psychology and cognitive sciences General Dentistry Upper teeth Orthodontics Electronic Data Processing Mouth business.industry 05 social sciences Mandible Biomechanical Phenomena Bite force quotient Mouth opening Biting Mastication In degree business Tooth 030217 neurology & neurosurgery Geology |
| Zdroj: | Journal of Dental Research. 76:1751-1759 |
| ISSN: | 1544-0591 0022-0345 |
| Popis: | A potentially dangerous situation arises when an individual bites on hard and brittle food which suddenly breaks, since the impact velocity of the lower teeth onto the upper teeth after the food is broken can be high and may cause dental damage. The present experiments were designed to study the magnitude of the impact velocity after a sudden unloading at various initial bite forces, degrees of mouth opening, and distances of travel. Subjects were asked to perform a static biting task during which the resistance to the bite was suddenly removed. The upward mandible movement was arrested after a certain distance. The velocity of the lower teeth at impact was calculated just before the mandible came to a standstill in combinations of 4 different bite forces (100, 80, 60, and 40 N), 4 different initial degrees of mouth opening (33.5, 30.5, 27.5, and 24.5 mm), and 3 different distances of travel of the mandible (4.5, 3.0, and 1.5 mm). We found that the bite force rapidly declined after the unloading, resulting in a small impact velocity of the lower front teeth. This impact velocity largely depended on the magnitude of the initial bite force and the distance traveled; it was barely sensitive to variations in degree of initial mouth opening. The maximal velocity of the lower teeth was 0.43 m/s (at an initial bite force of 100 N). This maximum was reached after a distance of travel of about 4 mm in 12 ms. The data suggest that the rapid decline in bite force coupled with a limitation of impact velocity is due to the force-velocity properties of the active jaw muscles and is not caused by neural control. |
| Databáze: | OpenAIRE |
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