Narita Noriyuki, Ishii Tomohiro, Iwaki Sunao, Kamiya Kazunobu, Okubo Masakazu, Uchida Takeshi, Kantake Ikuo, Shibutani Koh
Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.
Department of Removable Prosthodontics, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.
Front Aging Neurosci. 2020 Jan 31;11:375. doi: 10.3389/fnagi.2019.00375. eCollection 2019.
The cognitive effects of wearing a denture are not well understood. This study was conducted to clarify the effects of denture use on prefrontal and chewing muscle activities, occlusal state, and subjective chewing ability in partially edentulous elderly individuals.
A total of 16 partially edentulous patients were enrolled. Chewing-related prefrontal cortex and jaw muscle activities were simultaneously examined using a functional near-infrared spectroscopy (fNIRS) device and electromyography, under the conditions of unwearing, and wearing a denture. Occlusal state and masticatory score were also determined under both conditions. Using multiple linear regression analysis, associations between prefrontal and chewing activities with wearing were examined using change rates.
Chewing rhythmicity was maintained under both conditions. As compared with unwearing, the wearing condition was associated with improved prefrontal cortex and chewing muscle activities, occlusal state in regard to force and area, and masticatory score. Also, prefrontal activities were positively associated with burst duration and peak amplitude in masseter (Mm) and temporal muscle activities, as well as masticatory scores. In contrast, prefrontal activities were negatively associated with occlusal force.
Wearing a denture induced a positive association between burst duration and peak amplitude in Mm and temporal muscle activities and prefrontal activity, which may indicate a parallel consolidation of prefrontal cortex and rhythmical chewing activities, as well as masticatory scores. On the other hand, denture use induced a negative association of occlusal force with prefrontal activities, which might suggest that prefrontal compensative associations for the physiocognitive acquisition depended on biomechanical efficacy gained by wearing a denture.
佩戴假牙对认知的影响尚未得到充分理解。本研究旨在阐明佩戴假牙对部分牙列缺损老年人前额叶和咀嚼肌活动、咬合状态及主观咀嚼能力的影响。
共纳入16例部分牙列缺损患者。使用功能近红外光谱（fNIRS）设备和肌电图，在不佩戴假牙和佩戴假牙的条件下，同时检测与咀嚼相关的前额叶皮质和颌肌活动。在两种条件下还测定了咬合状态和咀嚼评分。采用多元线性回归分析，使用变化率检验佩戴假牙时前额叶和咀嚼活动之间的关联。
在两种条件下均保持咀嚼节律。与不佩戴假牙相比，佩戴假牙的条件与前额叶皮质和咀嚼肌活动改善、力和面积方面的咬合状态以及咀嚼评分相关。此外，前额叶活动与咬肌（Mm）和颞肌活动的爆发持续时间和峰值幅度以及咀嚼评分呈正相关。相比之下，前额叶活动与咬合力呈负相关。
佩戴假牙导致Mm和颞肌活动的爆发持续时间和峰值幅度与前额叶活动之间呈正相关，这可能表明前额叶皮质与节律性咀嚼活动以及咀嚼评分同时巩固。另一方面，使用假牙导致咬合力与前额叶活动呈负相关，这可能表明前额叶对生理认知习得的代偿性关联取决于佩戴假牙获得的生物力学效能。
