Background and aim

Recent shifts in the distribution of Japan's population towards older ages, have meant that the chance of encountering patients with dementia in dental clinics is increasing. Many studies have shown that the brain volume decreases along with the progression of dementia. Although previous studies have reported a relationship between tooth loss or periodontitis and the onset of dementia, the pathological mechanisms underlying this association have not been elucidated. In this study, we aimed to examine the relationship between the oral condition and brain atrophy and to discuss how to adequately deal with patients with dementia.

Participants and methods

This cross-sectional study included 15 participants who underwent brain magnetic resonance imaging (MRI). The participants were 60 years or older and presented with cognitive decline, including Alzheimer's disease (AD) and mild cognitive impairment (MCI), diagnosed by a neurologist. We obtained information on the oral condition, lifestyle, cognitive function, and brain atrophy. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). MR images of each patient were analyzed using the voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) to provide a quantitative measure of the degree of brain atrophy.

Results

The study population included 4 male and 11 female patients. The mean age and mean number of present teeth were 75.9 years (SD 6.7) and 15.0 (SD 11.1), respectively. The median MMSE score was 25.6 (SD 3.7). The degree of atrophy of the whole brain was significantly correlated with the number of present teeth (ρ = −0.72, p < 0.05) and the presence of a daily exercise habit (ρ = −0.66, p < 0.05).

Conclusion

This study demonstrated that the number of present teeth could be an indicator of the progress of dementia. Preserving the teeth as well as the acquisition of a regular exercise habit might be important for preventing progression of dementia. Further research examining a larger study population and analyzing a greater number of factors is warranted.

中文翻译：

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老年人认知功能下降与脑萎缩与现牙数量的关系

背景和目标

日本人口分布最近向老年人迈进，这意味着在牙科诊所遇到痴呆症患者的机会在增加。许多研究表明，大脑体积随着痴呆症的进展而减少。尽管先前的研究已经报道了牙齿脱落或牙周炎与痴呆症的发病之间的关系，但尚未阐明这种关联的病理机制。在这项研究中，我们旨在检查口腔状况与脑萎缩之间的关系，并讨论如何充分治疗痴呆症患者。

参加者和方法

这项横断面研究包括15位接受了脑磁共振成像（MRI）的参与者。参与者年龄在60岁或60岁以上，并表现出认知能力下降，包括神经学家诊断的阿尔茨海默氏病（AD）和轻度认知障碍（MCI）。我们获得了有关口腔状况，生活方式，认知功能和脑萎缩的信息。认知功能使用迷你精神状态检查（MMSE）进行评估。使用基于体素的阿尔茨海默氏病特定区域分析系统（VSRAD）对每位患者的MR图像进行分析，以定量评估脑萎缩程度。

结果

研究人群包括4名男性和11名女性患者。目前牙齿的平均年龄和平均数量分别为75.9年（SD 6.7）和15.0（SD 11.1）。MMSE中位数为25.6（SD 3.7）。整个大脑的萎缩程度与当前牙齿的数量（ρ= -0.72，p <0.05）和日常锻炼习惯的存在显着相关（ρ= -0.66，p <0.05）。

结论

这项研究表明，目前的牙齿数量可能是痴呆症进展的指标。保持牙齿以及养成规律的锻炼习惯对于预防痴呆症的进展可能很重要。有必要进行进一步的研究，以研究更大的研究人群并分析更多因素。