Publications by authors named "Yoshitada Miyoshi"
Objective: In this study, we aimed to examine the longitudinal association between combination of remaining natural teeth (RNT) and functional teeth (FT) or occlusal force (OF), with functional disability and mortality among community-dwelling Japanese adults aged ≥70 years with less than 20 remaining teeth.
Methods: The participants included 916 community-dwelling Japanese adults aged 70 years or older in 2003. Exposures were defined as a combination of RNT and either FT or OF.
Number of teeth and functional disability in community-dwelling older adults.
Gerodontology
March 2025
Introduction: This study determined whether tooth loss was associated with the development of functional disability and estimated the population attributable fraction (PAF) of functional disability due to tooth loss, along with risk factors for functional disability such as physical function and cognitive impairment.
Methods: The participants were 838 community-dwelling older adults aged ≥70 years living in the Tsurugaya district in Japan in 2003. The exposure variable was the number of remaining teeth (counted by trained dentists).
Article Synopsis
- This study explored the relationship between the number of teeth and hippocampal atrophy, particularly looking at how periodontitis severity may influence this link in older adults.
- Researchers analyzed data from 172 participants aged 55 and older, using brain MRI and dental assessments taken over a 4-year period to measure changes in hippocampal volume.
- Findings indicated that a higher number of teeth was associated with less hippocampal atrophy in individuals with low periodontitis severity, while the opposite was true for those with severe periodontitis, suggesting that dental health may play a role in brain health.
Regular dental visits, periodontitis, tooth loss, and atherosclerosis: The Ohasama study.
J Periodontal Res
June 2022
Objective: We aimed to explore the association between regular dental visits and atherosclerosis and between periodontitis, number of remaining teeth, and atherosclerosis among community dwellers in Japan.
Background: Few studies have examined the association between regular dental visits, periodontitis, tooth loss, and atherosclerosis in community dwellers in Japan.
Methods: The participants of this cross-sectional study included community dwellers aged ≥55 years and residing in Ohasama.
Globally, the cancer burden is expected to increase as populations are ageing. Therefore, cancer prevention among older age groups is important. This prospective cohort study examined the relationship between the number of remaining teeth, maximum occlusal force, and incidence of gastrointestinal cancer in community-dwelling older Japanese individuals using data from the Tsurugaya project; 847 participants were included.
View Article and Find Full Text PDFObjective: This prospective study investigated the cross-sectional association between impaired oral health-related quality of life (OHRQoL) and the prevalence of depressive symptoms, and the longitudinal association between impaired OHRQoL and development of depressive symptoms among older adults.
Background: Previous studies have shown a relationship between poor oral health and depression among older adults; however, findings are inconsistent.
Materials And Methods: Participants were 669 community-dwelling older Japanese individuals aged≥55 years (mean: 67.
Objective: This cross-sectional study aims to examine if cognitive impairment, depressive symptoms, and their combination are associated with biases between self-evaluated and measured masticatory performance in community-dwelling older Japanese adults.
Methods: The sample constituted of 804 community-dwelling elderly Japanese individuals aged ≥70 years. Cognitive impairment and depressive symptoms were assessed using the Mini-Mental State Examination and Geriatric Depression Scale, respectively.
Article Synopsis
- In 2016, the Japanese Society of Gerodontology introduced the concept of "oral hypofunction" and set initial criteria for reduced occlusal force, which were <200 N of maximum occlusal force and <20 remaining teeth, but recommended further evidence to validate these standards.
- A study involving 815 elderly Japanese adults showed that both MOF <200 N and <20 teeth were linked to a higher risk of functional disability, indicating some validity in the initial criteria.
- However, the research also suggested that the optimal cut-off values for predicting functional disabilities were actually 264.6 N for MOF and 19 teeth, highlighting the need for further studies to refine these diagnostic criteria.
Purpose: This study aimed to investigate the relationship between the bilateral maximum occlusal force (MOF) of full dental arches and all-cause mortality in a group of community-dwelling older males and females in Japan.
Methods: This 13-year prospective cohort study was conducted among 815 older adults (395 male and 420 female) aged 70 years or over (mean age ± standard deviation: 75.1 ± 4.
Background: Numerous prospective studies have investigated the association between the number of remaining teeth and dementia or cognitive decline. However, no agreement has emerged on the association between tooth loss and cognitive impairment, possibly due to past studies differing in target groups and methodologies. We aimed to investigate the association between tooth loss, as evaluated through clinical oral examinations, and the development of cognitive impairment in community-dwelling older adults while considering baseline cognitive function.
View Article and Find Full Text PDFPurpose: The purpose of this study was to examine whether the status of dentition is associated with incident functional disability in elderly people.
Methods: This prospective cohort study targeted community-dwelling Japanese adults of age ≥70 years (n=838). Participants were classified into the following four groups in accordance with Miyachi's Triangular Classification, which represents the status of dentition on the basis of numbers of remaining teeth and occlusal supports: Zone A, ≥10 occlusal supports; Zone B, 5-9 occlusal supports; Zone D, ≤4 occlusal supports and ≥11 remaining teeth and Zone C, ≤10 remaining teeth.
Objectives: To examine whether number of remaining teeth and regular dental care affect incident functional disability in elderly Japanese adults.
Design: Prospective cohort study.
Setting: Tsurugaya district, Sendai, Japan.