Associations between measured masticatory function and cognitive status: A systematic review

Kenji Maekawa; Yoshiko Motohashi; Kentaro Igarashi; Takuya Mino; Yasuhiko Kawai; Youngnam Kang; Toshihiro Hirai; Takuo Kuboki

doi:10.1111/ger.12751

Associations between measured masticatory function and cognitive status: A systematic review

Gerodontology. 2024 Mar 27. doi: 10.1111/ger.12751. Online ahead of print.

Authors

Kenji Maekawa¹, Yoshiko Motohashi², Kentaro Igarashi³, Takuya Mino¹, Yasuhiko Kawai³, Youngnam Kang⁴, Toshihiro Hirai⁵, Takuo Kuboki⁶

Affiliations

¹ Department of Removable Prosthodontics and Occlusion, Osaka Dental University, Osaka, Japan.
² Research Team for Promoting Independence and Mental Health, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
³ Removable Prosthodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
⁴ Department of Behavioral Sciences, Graduate School of Human Sciences, Osaka University, Osaka, Japan.
⁵ Department of Dentistry, Removable Prosthodontics, Health Sciences University of Hokkaido School of Dentistry, Hokkaido, Japan.
⁶ Department of Oral Rehabilitation and Regenerative Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Research Institute of Academic and Research, Okayama, Japan.

PMID: 38544306
DOI: 10.1111/ger.12751

Abstract

Objective: This systematic review aimed to provide an overview of the most recent evidence on the association between measured masticatory function and cognitive status.

Materials and methods: Literature and manual searches were conducted using three electronic databases (PubMed, Web of Science and CINAHL). Observational studies published between 2011 and 2021 investigating the association between masticatory function, dementia and cognitive status in adult humans were abstracted and reviewed by three reviewers. Studies that assessed participants' masticatory function using objective and subjective measurements and that individually examined its association with cognitive function were included. The included studies were divided into cross-sectional and cohort studies, and the quality of each study was analysed using critical appraisal skills checklists. Additionally, the main conclusions and strength of the evidence were assessed for each article.

Results: A total of 21 studies (11 cross-sectional studies that objectively evaluated masticatory function, 9 cross-sectional studies that subjectively evaluated masticatory function and 1 prospective cohort study) were evaluated. The poorer masticatory function was associated with lower cognitive status even after adjusting for potential risk factors of dementia in four of 11 and six of nine cross-sectional studies where the masticatory function was respectively evaluated objectively and subjectively. One prospective cohort study also demonstrated that masticatory function, as evaluated based on measurements of occlusal force, predicted cognitive decline during the follow-up period.

Conclusion: Several studies demonstrated a positive association between masticatory function and cognitive status. However, further studies, particularly longitudinal studies, are required to determine whether the association is causal.

Keywords: chewing; cognitive impairment; community‐dwelling adult; dementia; masticatory function; teeth.

Publication types

Review