Abstract：
BACKGROUND: Oral food processing is an important part of daily food intake. A major part of this process is mastication, which prepares a bolus of food for swallowing by mechanically crushing and grinding ingested food between the teeth using rhythmic movements. Masticatory dysfunction is common in the elderly and in some neurological disorders and can have serious negative health consequences.
OBJECTIVE: This study investigated the effect of restricted mastication, achieved by experimentally reducing the duration of mastication, on masticatory patterns and subsequent swallowing function.
METHODS: Thirty healthy men (25 ± 3 years old) were instructed to chew gum jelly with a free mastication duration (G100), a half and a quarter duration of G100. Masseter and digastric electromyographic (EMG) activity was recorded to assess mastication and swallowing activity, respectively. In addition, the acceleration of the thyroid cartilage ridge was measured with an accelerometer. The root mean square (RMS) of muscle EMG activity in the masseter and digastric muscles, the number of masseter EMG bursts, time to peak and total duration of each masseter EMG burst, swallowing duration and laryngeal elevation latency were analysed.
RESULTS: Restricting masticatory duration reduced the number of mastication cycles (p < .001), prolonged the time to peak (p < .001) and total duration of masseter EMG bursts (p < .001) and resulted in an overall increased RMS score of masseter muscle activity (p = .017). Furthermore, restricted masticatory duration led to a decrease in both swallowing duration (p = .001) and laryngeal elevation latency (p = .012), with a significant increase in the RMS score of digastric muscle activity (p < .001).
CONCLUSIONS: Under the experimental conditions of restricted mastication, several adaptation features were observed, including changes in masticatory cycle characteristics and swallowing duration. Thus, although the overall masticatory efficiency was reduced, these adaptations allowed healthy individuals to still swallow safely.
OBJECTIVE: This study investigated the effect of restricted mastication, achieved by experimentally reducing the duration of mastication, on masticatory patterns and subsequent swallowing function.
METHODS: Thirty healthy men (25 ± 3 years old) were instructed to chew gum jelly with a free mastication duration (G100), a half and a quarter duration of G100. Masseter and digastric electromyographic (EMG) activity was recorded to assess mastication and swallowing activity, respectively. In addition, the acceleration of the thyroid cartilage ridge was measured with an accelerometer. The root mean square (RMS) of muscle EMG activity in the masseter and digastric muscles, the number of masseter EMG bursts, time to peak and total duration of each masseter EMG burst, swallowing duration and laryngeal elevation latency were analysed.
RESULTS: Restricting masticatory duration reduced the number of mastication cycles (p < .001), prolonged the time to peak (p < .001) and total duration of masseter EMG bursts (p < .001) and resulted in an overall increased RMS score of masseter muscle activity (p = .017). Furthermore, restricted masticatory duration led to a decrease in both swallowing duration (p = .001) and laryngeal elevation latency (p = .012), with a significant increase in the RMS score of digastric muscle activity (p < .001).
CONCLUSIONS: Under the experimental conditions of restricted mastication, several adaptation features were observed, including changes in masticatory cycle characteristics and swallowing duration. Thus, although the overall masticatory efficiency was reduced, these adaptations allowed healthy individuals to still swallow safely.
摘要：
背景：口服食物加工是日常食物摄入的重要组成部分。这个过程的主要部分是咀嚼，它通过使用有节奏的运动在牙齿之间机械地压碎和研磨摄取的食物来准备用于吞咽的食物。咀嚼功能障碍在老年人和一些神经系统疾病中很常见，可能会产生严重的负面健康后果。
目的：本研究调查了限制咀嚼的效果，通过实验减少咀嚼时间来实现，咀嚼模式和随后的吞咽功能。
方法：30名健康男性（25±3岁）被指示以自由咀嚼时间（G100）咀嚼口香糖果冻，G100的半和四分之一的持续时间。记录咬肌和腹肌肌电图（EMG）活动以评估咀嚼和吞咽活动，分别。此外,用加速度计测量甲状软骨脊的加速度。咬肌和腹肌肌电图活动的均方根（RMS），咬肌肌电图的爆发次数,每个咬肌肌电图爆发的峰值时间和总持续时间，分析吞咽持续时间和喉抬高潜伏期。
结果：限制咀嚼持续时间减少了咀嚼周期的数量（p<.001），延长了达到峰值的时间（p<.001）和咬肌肌电图爆发的总持续时间（p<.001），并导致咬肌活动的RMS评分总体增加（p=.017）。此外，限制咀嚼持续时间导致吞咽持续时间（p=.001）和喉抬高潜伏期（p=.012）减少，腹肌活动的RMS评分显着增加（p<.001）。
结论：在限制咀嚼的实验条件下，观察到几个适应特征，包括咀嚼周期特征和吞咽持续时间的变化。因此，虽然整体咀嚼效率降低，这些适应使健康个体仍然可以安全地吞咽。
目的：本研究调查了限制咀嚼的效果，通过实验减少咀嚼时间来实现，咀嚼模式和随后的吞咽功能。
方法：30名健康男性（25±3岁）被指示以自由咀嚼时间（G100）咀嚼口香糖果冻，G100的半和四分之一的持续时间。记录咬肌和腹肌肌电图（EMG）活动以评估咀嚼和吞咽活动，分别。此外,用加速度计测量甲状软骨脊的加速度。咬肌和腹肌肌电图活动的均方根（RMS），咬肌肌电图的爆发次数,每个咬肌肌电图爆发的峰值时间和总持续时间，分析吞咽持续时间和喉抬高潜伏期。
结果：限制咀嚼持续时间减少了咀嚼周期的数量（p<.001），延长了达到峰值的时间（p<.001）和咬肌肌电图爆发的总持续时间（p<.001），并导致咬肌活动的RMS评分总体增加（p=.017）。此外，限制咀嚼持续时间导致吞咽持续时间（p=.001）和喉抬高潜伏期（p=.012）减少，腹肌活动的RMS评分显着增加（p<.001）。
结论：在限制咀嚼的实验条件下，观察到几个适应特征，包括咀嚼周期特征和吞咽持续时间的变化。因此，虽然整体咀嚼效率降低，这些适应使健康个体仍然可以安全地吞咽。
