Department of Biologic and Materials Sciences, School of Dentistry, Ann Arbor, MI 48109-1078, USA.
Arch Oral Biol. 2013 Oct;58(10):1464-74. doi: 10.1016/j.archoralbio.2013.06.009. Epub 2013 Jul 31.
The study investigated modulation of fast and slow opening (FO, SO) and closing (FC, SC) chewing cycle phases using gum-chewing sequences in humans.
Twenty-two healthy adult subjects participated by chewing gum for at least 20s on the right side and at least 20s on the left side while jaw movements were tracked with a 3D motion analysis system. Jaw movement data were digitized, and chewing cycle phases were identified and analysed for all chewing cycles in a complete sequence.
All four chewing cycle phase durations were more variant than total cycle durations, a result found in other non-human primates. Significant negative correlations existed between the opening phases, SO and FO, and between the closing phases, SC and FC; however, there was less consistency in terms of which phases were negatively correlated both between subjects, and between chewing sides within subjects, compared with results reported in other species.
The coordination of intra-cycle phases appears to be flexible and to follow complex rules during gum-chewing in humans. Alternatively, the observed intra-cycle phase relationships could simply reflect: (1) variation in jaw kinematics due to variation in how gum was handled by the tongue on a chew-by-chew basis in our experimental design or (2) by variation due to data sampling noise and/or how phases were defined and identified.
本研究旨在通过人类咀嚼口香糖的序列，研究咀嚼循环的快开（FO）、慢开（SO）、快闭（FC）和慢闭（SC）阶段的调制。
22 名健康成年受试者用右侧咀嚼至少 20 秒，用左侧咀嚼至少 20 秒，同时使用三维运动分析系统跟踪下颌运动。对下颌运动数据进行数字化处理，对完整序列中的所有咀嚼周期进行咀嚼周期相位的识别和分析。
与其他非人类灵长类动物一样，所有四个咀嚼周期相位的持续时间都比总周期持续时间更具变异性。开口相位 SO 和 FO 之间，以及闭合相位 SC 和 FC 之间存在显著的负相关关系；然而，与其他物种的结果相比，在受试者之间，以及在受试者的咀嚼侧之间，哪些相位存在负相关的一致性较小。
在人类咀嚼口香糖时，内循环相位的协调似乎是灵活的，并遵循复杂的规则。或者，观察到的内循环相位关系可能仅仅反映了：（1）在我们的实验设计中，由于舌头在每一次咀嚼中处理口香糖的方式不同，导致颌运动的变化；或者（2）由于数据采样噪声以及相位的定义和识别方式的不同而导致的变化。
