Gao Chenyi, Kang Jing
School of Dentistry, University of Leeds, Leeds, UK.
Oral Clinical Research Unit, Centre of Clinical Translational Science, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, UK.
Adv Exp Med Biol. 2025;1472:171-183. doi: 10.1007/978-3-031-79146-8_11.
Common oral diseases, including periodontitis and dental caries, and their endpoint as tooth loss are controllable yet highly prevalent among adults worldwide. Cognitive decline also poses significant global public health challenges during the aging process, especially the pathological form of cognitive decline such as dementia. Dementia is irreversible and is one of the leading causes of death, disability, and dependency in the aging population. Emerging research suggests a bidirectional association between oral diseases and cognitive decline or dementia. This potential link has implications for designing better oral care plans for patients with dementia and recognizing oral diseases as modifiable risk factors for dementia prevention.This chapter provides an overview of the association between oral diseases and cognitive decline, followed by a discussion of current evidence on such associations in two directions: (1) the impact of cognitive decline or dementia on oral health and (2) the role of oral diseases as modifiable risk factors for dementia. We critically evaluate several hypotheses regarding the underlying mechanisms of this association, including (1) life-course hypothesis, (2) shared inflammation and bacterial infection mechanisms, (3) malnourishment mechanism, (4) pain pathway, and (5) sensory feedback pathway.However, the association between oral diseases and cognitive decline or dementia remains controversial due to limited high-quality evidence, particularly from biomedical research. Much of the existing evidence is from observational studies prone to confounding bias, with inconclusive questions about causation and the direction of causality.This chapter concludes by emphasizing the need for future studies with robust methodological designs, including randomized controlled trials, biomedical studies, and innovative research techniques such as Mendelian randomization. Such studies are crucial for disease prevention and enhancing patient care and quality of life. By providing a comprehensive overview, this chapter contributes to an advanced understanding of this field, addresses current study gaps, and suggests future research directions.
常见的口腔疾病，包括牙周炎和龋齿，以及它们的最终结果——牙齿脱落，在全球成年人中是可控的，但却非常普遍。认知能力下降在衰老过程中也给全球公共卫生带来了重大挑战，尤其是认知能力下降的病理形式，如痴呆症。痴呆症是不可逆的，是老年人口死亡、残疾和依赖的主要原因之一。新兴研究表明，口腔疾病与认知能力下降或痴呆症之间存在双向关联。这种潜在联系对于为痴呆症患者设计更好的口腔护理计划以及将口腔疾病视为可改变的痴呆症预防风险因素具有重要意义。本章概述了口腔疾病与认知能力下降之间的关联，随后从两个方向讨论了关于这种关联的现有证据：（1）认知能力下降或痴呆症对口腔健康的影响；（2）口腔疾病作为可改变的痴呆症风险因素的作用。我们批判性地评估了关于这种关联潜在机制的几种假设，包括（1）生命历程假设；（2）共同的炎症和细菌感染机制；（3）营养不良机制；（4）疼痛通路；（5）感觉反馈通路。然而，由于高质量证据有限，尤其是来自生物医学研究的证据，口腔疾病与认知能力下降或痴呆症之间的关联仍然存在争议。现有的大部分证据来自容易产生混杂偏倚的观察性研究，关于因果关系和因果方向的问题尚无定论。本章最后强调了未来进行具有稳健方法设计的研究的必要性，包括随机对照试验、生物医学研究以及孟德尔随机化等创新研究技术。此类研究对于疾病预防以及提高患者护理和生活质量至关重要。通过提供全面的概述，本章有助于深入了解该领域，解决当前的研究空白，并提出未来的研究方向。
