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

采用功能磁共振成像（fMRI）技术，观察咀嚼运动时脑功能的变化.本研究中使用的fMRI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）被告知使用咬合板7天。分别于使用咬合板后第1、3、7天及取出咬合板后第7天进行fMRI检查。采集功能磁共振图像后，用视觉模拟量表记录受试者的主观感觉。使用SPM 2（统计参数映射2）分析fMRI数据，以确定使用和不使用咬合夹板之间的脑活动差异（p=0.001未校正，范围阈值= 20体素）。在使用咬合板的第1天，小脑和左侧额中回（BA10）在使用咬合板的情况下比不使用咬合板的情况下激活更多，表明小脑和额叶在“运动学习”过程中的激活。在使用咬合板的第3天和第7天，小脑和额叶的活动没有差异。结果表明，在去除咬合板后第7天，左侧运动前区皮层的激活程度明显高于无咬合板时，提示在去除咬合板后，与新的咀嚼运动模式相对应的脑神经网络得以建立和维持。尽管我们分析了VAS主观感觉评分与SPM 2脑活动之间的相关性，但未观察到显著相关性。

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.