Study of brain plasticity and functional and psychological adaptability caused by alteration of oral environment

我们使用功能磁共振图像（fMRI）评估大脑功能，以证明咀嚼的大脑活动变化。本研究中使用的功能磁共振成像采集协议已在我们的试点研究中进行了优化。 6 名成年男性受试者（平均年龄 23.2 岁）被告知使用咬合夹板 7 天。在使用咬合夹板的第 1、3、7 天和去除咬合夹板后的第 7 天进行功能磁共振成像。 fMRI采集后，用“视觉模拟量表”记录每个受试者的主观感觉。使用 SPM2（统计参数映射 2）分析 fMRI 数据，以确定有和没有咬合夹板之间大脑活动的差异（p = 0.001 未校正，范围阈值 = 20 体素）。在使用咬合夹板的第一天，使用咬合夹板时的小脑和左侧额中回（BA10）比不使用咬合板时更加活跃。这些结果表明小脑和额叶在“运动学习”过程中被激活。使用咬合夹板的第 3 天和第 7 天，小脑和额叶没有检测到活动差异。去除咬合夹板后第 7 天，使用咬合夹板时左前运动皮层比不使用咬合板时更加活跃。这些发现表明，在去除咬合夹板后，构建并维持了与新的咀嚼运动模式相对应的大脑神经网络。尽管我们使用 SPM2 分析了 VAS 主观感觉评分与大脑活动之间的关联，但没有观察到显着相关性。

We evaluated brain function using functional magnetic resonance image (fMRI) to demonstrate brain activity change of mastication. fMRI acquisition protocol used in the present study has been optimised in our pilot study. 6 adult male subjects (mean age 23.2) were told to use occlusal splint for 7 days. fMRI was performed on day 1, 3, 7 of occlusal splint use and day 7 after occlusal splint removal. After fMRI acquisition, subjective sensations of every subject were recorded with "Visual Analog Scale". fMRI data were analyzed with SPM2 (Statistical Parametric Mapping 2) to determine differences of brain activity between with and without occlusal Splint (p=0.001 uncorrected, extent threshold=20voxels). On day 1 of occlusal splint use, cerebellum and left middle frontal gyrus (BA10) were more activated with occlusal splint than without it. These results showed the activation of cerebellum and frontal lobe during "motor learning". On day 3 and 7 of occlusal splint use, no difference of activity was detected in cerebellum and frontal lobe. On day 7 after occlusal splint removal, left premotor cortex was more activated with occlusal splint than without it. These findings suggest that brain neural network corresponding to new pattern of masticatory movement was constructed and maintained after occlusal splint removal. Although we analyzed association between subjective sensation score by VAS and brain activity using SPM2, no significant correlation was observed.