Kobayashi T, Fukami H, Ishikawa E, Shibata K, Kubota M, Kondo H, Sahara Y
Department of Prosthodontics and Oral Implantology, School of Dentistry, Iwate Medical University, Morioka, Japan.
Department of Physiology, School of Dentistry, Iwate Medical University, Shiwa-gun, Japan.
Front Aging Neurosci. 2020 Mar 17;12:32. doi: 10.3389/fnagi.2020.00032. eCollection 2020.
Cortical activity during jaw movement has been analyzed using various non-invasive brain imaging methods, but the contribution of orofacial sensory input to voluntary jaw movements remains unclear. In this study, we used functional magnetic resonance imaging (fMRI) to observe brain activities during a simple teeth tapping task in adult dentulous (AD), older dentulous (OD), and older edentulous subjects who wore dentures (OEd) or did not wear dentures (OE) to analyze their functional network connections. (1) To assess the effect of age on natural activation patterns during teeth tapping, a comparison of groups with natural dentition-AD and OD-was undertaken. A general linear model analysis indicated that the major activated site in the AD group was the primary sensory cortex (SI) and motor cortex (MI) ( < 0.05, family wise error corrected). In the OD group, teeth tapping induced brain activity at various foci ( < 0.05, family wise error corrected), including the SI, MI, insula cortex, supplementary motor cortex (SMC)/premotor cortex (PMA), cerebellum, thalamus, and basal ganglia in each group. (2) Group comparisons between the OD and OEd subjects showed decreased activity in the SI, MI, Brodmann's area 6 (BA6), thalamus (ventral posteromedial nucleus, VPM), basal ganglia, and insular cortex ( ¡ 0.005, uncorrected). This suggested that the decreased S1/M1 activity in the OEd group was related to missing teeth, which led to reduced periodontal afferents. (3) A conjunction analysis in the OD and OEd/OE groups revealed that commonly activated areas were the MI, SI, cerebellum, BA6, thalamus (VPM), and basal ganglia (putamen; < 0.05, FWE corrected). These areas have been associated with voluntary movements. (4) Psychophysiological interaction analysis (OEd vs OE) showed that subcortical and cortical structures, such as the MI, SI, DLPFC, SMC/PMA, insula cortex, basal ganglia, and cerebellum, likely function as hubs and form an integrated network that participates in the control of teeth tapping. These results suggest that oral sensory inputs are involved in the control of teeth tapping through feedforward control of intended movements, as well as feedback control of ongoing movements.
人们已使用各种非侵入性脑成像方法分析了下颌运动期间的皮质活动，但口腔面部感觉输入对自主下颌运动的作用仍不清楚。在本研究中，我们使用功能磁共振成像（fMRI）观察成年有牙（AD）、老年有牙（OD）以及佩戴假牙（OEd）或未佩戴假牙（OE）的老年无牙受试者在简单叩齿任务期间的脑活动，以分析其功能网络连接。（1）为评估年龄对叩齿期间自然激活模式的影响，对有天然牙列的组（AD和OD）进行了比较。一般线性模型分析表明，AD组的主要激活部位是初级感觉皮层（SI）和运动皮层（MI）（<0.05，经家族性错误校正）。在OD组中，叩齿在多个部位诱发了脑活动（<0.05，经家族性错误校正），每组包括SI、MI、岛叶皮层、辅助运动皮层（SMC）/运动前皮层（PMA）、小脑、丘脑和基底神经节。（2）OD组与OEd组受试者之间的组间比较显示，SI、MI、布罗德曼6区（BA6）、丘脑（腹后内侧核，VPM）、基底神经节和岛叶皮层的活动减少（<0.005，未校正）。这表明OEd组中S1/M1活动的减少与牙齿缺失有关，牙齿缺失导致牙周传入减少。（3）OD组与OEd/OE组的联合分析显示，共同激活的区域是MI、SI、小脑、BA6、丘脑（VPM）和基底神经节（壳核；<0.05，经FWE校正）。这些区域与自主运动有关。（4）心理生理交互作用分析（OEd与OE）表明，皮层下和皮层结构，如MI、SI、背外侧前额叶皮层（DLPFC）、SMC/PMA、岛叶皮层、基底神经节和小脑，可能起到枢纽作用并形成一个参与控制叩齿的整合网络。这些结果表明，口腔感觉输入通过对预期运动的前馈控制以及对正在进行运动的反馈控制参与叩齿的控制。
