Lin Chia-Shu
Department of Dentistry, School of Dentistry, National Yang-Ming University, Taipei, Taiwan.
Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Front Aging Neurosci. 2020 Jan 9;11:354. doi: 10.3389/fnagi.2019.00354. eCollection 2019.
"Practice makes perfect" is a principle widely applied when one is acquiring a new sensorimotor skill to cope with challenges from a new environment. In terms of oral healthcare, the traditional view holds that restoring decayed structures is one of the primary aims of treatment. This assumes that the patient's oromotor functions would be recovered back to normal levels after the restoration. However, in older patients, such a structural-functional coupling after dental treatment shows a great degree of individual variations. For example, after prosthodontic treatment, some patients would adapt themselves quickly to the new dentures, while others would not. In this Focused Review, I argue that the functional aspects of adaptation-which would be predominantly associated with the brain mechanisms of cognitive processing and motor learning-play a critical role in the individual differences in the adaptive behaviors of oromotor functions. This thesis is critical to geriatric oral healthcare since the variation in the capacity of cognitive processing and motor learning is critically associated with aging. In this review, (a) the association between aging and the brain-stomatognathic axis will be introduced; (b) the brain mechanisms underlying the association between aging, compensatory behavior, and motor learning will be briefly summarized; (c) the neuroimaging evidence that suggests the role of cognitive processing and motor learning in oromotor functions will be summarized, and critically, the brain mechanisms underlying mastication and swallowing in older people will be discussed; and (d) based on the current knowledge, an experimental framework for investigating the association between aging and the functional adaptation of oromotor functions will be proposed. Finally, I will comment on the practical implications of this framework and postulate questions open for future research.
“熟能生巧”是一条被广泛应用的原则，当一个人在获取一项新的感觉运动技能以应对新环境带来的挑战时。就口腔保健而言，传统观点认为修复龋损结构是治疗的主要目标之一。这假定在修复后患者的口面部运动功能将恢复到正常水平。然而，在老年患者中，牙科治疗后的这种结构 - 功能耦合表现出很大程度的个体差异。例如，在进行假牙修复治疗后，一些患者能很快适应新假牙，而另一些患者则不能。在这篇聚焦综述中，我认为适应的功能方面——这主要与认知加工和运动学习的脑机制相关——在口面部运动功能适应性行为的个体差异中起关键作用。这一论点对老年口腔保健至关重要，因为认知加工和运动学习能力的变化与衰老密切相关。在这篇综述中，（a）将介绍衰老与脑 - 口颌系统轴之间的关联；（b）将简要总结衰老、代偿行为和运动学习之间关联的脑机制；（c）将总结表明认知加工和运动学习在口面部运动功能中作用的神经影像学证据，并且关键的是，将讨论老年人咀嚼和吞咽的脑机制；以及（d）基于当前的知识，将提出一个用于研究衰老与口面部运动功能功能适应性之间关联的实验框架。最后，我将对这个框架的实际意义进行评论，并提出有待未来研究的开放性问题。
