Treffel Loïc, Dmitrieva Liubov, Gauquelin-Koch Guillemette, Custaud Marc-Antoine, Blanc Stéphane, Gharib Claude, Millet Catherine
Université Claude Bernard Lyon 1, Lyon, France.
Université de Strasbourg, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7178, Strasbourg, France.
PLoS One. 2016 Feb 25;11(2):e0150052. doi: 10.1371/journal.pone.0150052. eCollection 2016.
The objective of the study was to determine the influence of simulated microgravity by exposure to dry immersion on the craniomandibular system. Twelve healthy male volunteers participated in a 3-day dry immersion study. Before and immediately after exposure we measured maximal bite force using piezoresistive sensors. The mechanical properties of the jaw and cervical muscles were evaluated before, during, and after dry immersion using MyotonPRO. Because recent studies reported the effects of jaw motor activity on the postural stability of humans, stabilometric measurements of center of pressure were performed before and after dry immersion in two mandibular positions: rest position without jaw clenching, and intercuspidal position during voluntary teeth clenching. Results revealed no significant changes of maximal bite force after dry immersion. All postural parameters were significantly altered by dry immersion. There were however no significant differences in stabilometric data according to mandibular position. Moreover the masseter tonicity increased immediately after the end of dry immersion period. Dry immersion could be used as a valid model for studying the effects of microgravity on human subjects. However, 3 days appear insufficient in duration to evaluate the effects of weightlessness on maximal bite force. Our research suggests a link between postural disturbance after dry immersion and masseter tonicity.
本研究的目的是确定通过干式浸没模拟微重力对颅下颌系统的影响。12名健康男性志愿者参与了一项为期3天的干式浸没研究。在暴露前和暴露后立即使用压阻式传感器测量最大咬合力。在干式浸没前、浸没期间和浸没后使用MyotonPRO评估颌骨和颈部肌肉的力学性能。由于最近的研究报道了颌骨运动活动对人体姿势稳定性的影响，因此在干式浸没前后在两个下颌位置进行了压力中心的稳定测量：无颌骨紧闭的休息位和自愿咬牙时的尖牙间位。结果显示干式浸没后最大咬合力无显著变化。所有姿势参数均因干式浸没而发生显著改变。然而，根据下颌位置，稳定测量数据没有显著差异。此外，在干式浸没期结束后，咬肌张力立即增加。干式浸没可作为研究微重力对人体影响的有效模型。然而，3天的持续时间似乎不足以评估失重对最大咬合力的影响。我们的研究表明干式浸没后的姿势紊乱与咬肌张力之间存在联系。
