Hysteresis in jaw positioning following lateral stretches
| Autor: | F. B. Dal Santo, Robert R. Lemke, John D. Rugh |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Adult
Male Reflex Stretch Analysis of Variance Materials science Time Factors Electromyography Muscle Relaxation Lateral positioning Mandible Healthy subjects Biofeedback Psychology Anatomy Masticatory force Hysteresis (economics) Jaw Relation Record Masticatory Muscles Humans Female Emg biofeedback Least-Squares Analysis General Dentistry Muscle Contraction |
| Zdroj: | Journal of dental research. 69(2) |
| ISSN: | 0022-0345 |
| Popis: | The purpose of this study was to examine hysteresis of the masticatory system following brief voluntary lateral positioning of the mandible. Hysteresis was studied in ten healthy subjects, as a function of both time and distance that the mandible was held laterally off the midline. So that the effects of distance of lateral stretch on hysteresis could be studied, subjects positioned their jaws to the left or right of the midline distances of 2, 4, 6, 8, and 10 mm for ten s. So that the effects of time could be studied, the distance of lateral stretch was held a constant 8 mm for durations of two, four, six, 12, 16, and 20 s. Following each voluntary lateral stretch, subjects relaxed the muscles using EMG biofeedback and allowed the mandible to reposition itself passively. Hysteresis was defined as the difference in the mandibular resting position between pre- and post-stretch recordings. Mean hysteresis effects ranged from 0.7 mm to 1.8 mm. Hysteresis effects were found to increase with both distance and time; after eight s, however, no additional effect of time was noted. |
| Databáze: | OpenAIRE |
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