RE MOUTH ACTIVITIES INVOLVED IN THE PROCESS OF COGNITIVE DISORDERS?-IN SEARCH OF NEUROPATHOLOGIC ASSOCIATIONS-

戴义齿被认为可以改善老年人的咀嚼能力、咀嚼舒适性和生活质量。为了阐明义齿修复对参与高级认知功能的前额叶皮质激活的影响，我们从认知功能和颌骨功能以及相关的前额叶皮质活动的角度研究了义齿修复的效果。受试者为部分无牙颌患者。采用功能性近红外光谱(f-NIRS)检测前额叶皮质区脑血流的变化，同时采用问卷调查(SF36 v2、OHIP-J和MMSE)检测认知功能，同时检测颌肌肌电和运动活动。同时用咀嚼功能评分评价患者的主观意识和咀嚼能力意识。对戴义齿和不戴义齿时获得的数据进行统计比较。与咀嚼相关的功能，包括下颌运动、下颌肌肉肌电和前额皮质活动，显著增加，而与未佩戴义齿相比，戴部分义齿的咀嚼分数也显著提高。佩戴义齿修复引起的前额叶皮质活动与咀嚼评分和咀嚼肌电活动显著相关。在义齿治疗过程中，患者的牙科生活质量、生理生活质量和MMSE评分均较治疗前有改善趋势。基于我们的发现，我们认为义齿修复体的牙科治疗不仅有助于改善咀嚼功能，还有助于改善认知能力，如前额叶皮质的激活以及口腔和身体生活质量的认知得分。

Denture wearing is considered to improve chewing ability, chewing comfort, and quality of life(QOL) in elderly individuals. In order to clarify the effects of denture treatment on activation of the prefrontal cortex, which is involved in higher cognitive functions, we investigated the efficacy of wearing a denture prosthesis from the aspects of cognitive and jaw functions, and related prefrontal cortex activity. Partially edentulous patients were enlisted as subjects. Functional near infrared spectroscopy(f-NIRS) was used to detect changes of cerebral blood flow in the prefrontal cortex area, while cognitive functions were examined using questionnaires(SF36 v2, OHIP-J, and MMSE : Mini-mental state examination), with jaw muscle EMG and motions activities simultaneously investigated. Masticatory scores were also used to evaluate subjective awareness and consciousness of chewing ability. Statistical comparisons were performed between data obtained while wearing and not wearing a denture prosthesis. Significant increases were seen in chewing-related jaw functions, including jaw motion, jaw muscle EMG, and prefrontal cortex activity, while masticatory scores were also significantly improved by wearing a partial denture prosthesis as compared with the non-wearing condition. Prefrontal cortex activity caused by a wearing denture prosthesis was significantly related to masticatory score and masticatory EMG activities. During the process of denture treatment, the scores of dental and physical QOL, and MMSE showed improving trends as compared to the pre-therapeutic conditions. Based on our findings, we consider that dental treatment with a denture prosthesis may help to improve not only masticatory jaw functions, but also cognitive ability, as shown by prefrontal cortex activation and cognitive scores for oral and physical QOL.