Department of Dentistry, School of Dentistry, National Yang-Ming University, Taipei City, Taiwan.
Institute of Brain Science, National Yang-Ming University, Taipei City, Taiwan.
Brain Imaging Behav. 2020 Apr;14(2):396-407. doi: 10.1007/s11682-020-00267-w.
Previous studies have reported an association between tooth loss and gray matter volume (GMV) in healthy adults. The study aims to elucidate the link between tooth loss, brain volume differences, and cognitive impairment by investigating the total and regional differences in GMV associated with tooth loss in older people with and without cognitive impairment. Forty older participants with mild cognitive impairment or Alzheimer's disease [the cognitive impairment (CI) group] and 30 age- and sex-matched healthy participants [the control (CON) group] received T1-weighted magnetic resonance imaging scans and assessments of oral functions, including masticatory performance (MP) and the number of missing teeth (NMT). Voxel-based morphometry was used to assess the total and regional GMV, including that of the medial temporal lobe and motor-related areas. (A) When the total intracranial volume and age were controlled for, an increased MP was associated with a larger GMV in the premotor cortex in the CON group. (B) In the CI group, an increased NMT was significantly correlated with smaller regional GMV of the bilateral primary motor cortex and the premotor cortex. (C) In the CI group, but not the CON group, an increased NMT was associated with both smaller total GMV and regional GMV of the left medial temporal lobe, including the left hippocampus and parahippocampus. Tooth loss may be preferentially related to the structural differences in the medial temporal lobe in cognitively impaired older people. Further research is required to understand the mechanisms of the relationships.
先前的研究报告称，在健康成年人中，牙齿缺失与灰质体积（GMV）之间存在关联。本研究旨在通过调查与认知障碍（CI）和无认知障碍（CON）老年人牙齿缺失相关的 GMV 的总差异和区域差异，阐明牙齿缺失、脑容量差异与认知障碍之间的联系。40 名患有轻度认知障碍或阿尔茨海默病的老年人（CI 组）和 30 名年龄和性别匹配的健康参与者（CON 组）接受了 T1 加权磁共振成像扫描和口腔功能评估，包括咀嚼性能（MP）和缺牙数量（NMT）。基于体素的形态测量法用于评估 GMV 的总差异和区域差异，包括内侧颞叶和运动相关区域。（A）当控制总颅内体积和年龄时，CON 组中 MP 的增加与运动前皮质 GMV 的增加相关。（B）在 CI 组中，NMT 的增加与双侧初级运动皮质和运动前皮质的 GMV 区域的减小显著相关。（C）在 CI 组中，但不在 CON 组中，NMT 的增加与左内侧颞叶（包括左海马和海马旁回）的总 GMV 和 GMV 区域的减小均相关。牙齿缺失可能与认知障碍老年人内侧颞叶的结构差异有关。需要进一步研究以了解这些关系的机制。
