Fujishita A, Koga Y, Utsumi D, Nakamura A, Yoshimi T, Yoshida N
Department of Orthodontics and Dentofacial Orthopedics, Graduate school of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
J Oral Rehabil. 2015 Apr;42(4):266-74. doi: 10.1111/joor.12248. Epub 2014 Oct 30.
It has been suggested that feeding a soft diet could possibly inhibit normal development of the masticatory function. However, the consequences of such changes in the alimentary habits have yet to be fully clarified. Therefore, the aim of this study was to determine whether a soft diet prevents the development of masticatory function and whether a critical period for programming the masticatory system exists. To examine these hypotheses, we used a three-dimensional jaw-movement tracking device and jaw muscle electromyography (EMG) to analyse masticatory function changes in mice. Jcl:ICR mice were divided into three groups, with the normal group fed a hard diet, the hypofunctional group fed a soft diet, and the rehabilitation group first fed a soft diet that was then changed to a hard diet. Our results showed that the excursion and duration of late-closing phase (occlusal phase) of the chewing cycle and EMG activity in the masseter muscle were not only reduced in the hypofunctional but also in the rehabilitation group as compared with the normal group. These results suggest that optimisation of the chewing pattern and acquisition of appropriate masticatory function are impeded by feeding a soft diet during the animal's growth period and that no catch-up effect of the masticatory function is observed when there is a prolonged period of time prior to changing the diet from soft to hard. In conclusion, masticatory function can only be fully developed through a learning process such as exposure to chewing various kinds of foods with different food textures.
有人提出，食用软质饮食可能会抑制咀嚼功能的正常发育。然而，这种饮食习惯变化的后果尚未完全阐明。因此，本研究的目的是确定软质饮食是否会阻碍咀嚼功能的发育，以及咀嚼系统编程是否存在关键期。为了验证这些假设，我们使用三维颌骨运动跟踪装置和颌骨肌肉肌电图（EMG）来分析小鼠咀嚼功能的变化。将Jcl:ICR小鼠分为三组，正常组喂食硬质饮食，功能减退组喂食软质饮食，康复组先喂食软质饮食，然后改为硬质饮食。我们的结果表明，与正常组相比，功能减退组和康复组咀嚼周期的后期闭合阶段（咬合阶段）的偏移和持续时间以及咬肌的肌电图活动均降低。这些结果表明，在动物生长期间喂食软质饮食会阻碍咀嚼模式的优化和适当咀嚼功能的获得，并且在将饮食从软质改为硬质之前如果有较长时间，咀嚼功能不会出现追赶效应。总之，咀嚼功能只能通过学习过程来充分发育，例如接触咀嚼各种具有不同食物质地的食物。
