@article{pmid37407259,

title = {Associations of Dental Health With the Progression of Hippocampal Atrophy in Community-Dwelling Individuals: The Ohasama Study},

author = {Satoshi Yamaguchi and Takahisa Murakami and Michihiro Satoh and Takamasa Komiyama and Takashi Ohi and Yoshitada Miyoshi and Kosei Endo and Takako Hiratsuka and Azusa Hara and Yukako Tatsumi and Tomoko Totsune and Kei Asayama and Masahiro Kikuya and Kyoko Nomura and Atsushi Hozawa and Hirohito Metoki and Yutaka Imai and Makoto Watanabe and Takayoshi Ohkubo and Yoshinori Hattori},

doi = {10.1212/WNL.0000000000207579},

issn = {1526-632X},

year  = {2023},

date = {2023-07-01},

journal = {Neurology},

abstract = {BACKGROUND AND OBJECTIVES: Although tooth loss and periodontitis have been considered risk factors for Alzheimer's disease, recent longitudinal researches have not found a significant association with hippocampal atrophy. Therefore, this study aimed to clarify a longitudinal association between the number of teeth present (NTP) and hippocampal atrophy dependent on the severity of periodontitis in a late middle-aged and older adult population.nnMETHODS: This study included community-dwelling individuals aged ≥55 years who had no cognitive decline and had undergone brain magnetic resonance imaging (MRI) and oral and systemic data collection twice at 4-year intervals. Hippocampal volumes were obtained from MRIs by automated region-of-interest analysis. The mean periodontal probing depth (mean PD) was used as a measure of periodontitis. Multiple regression analysis was performed with the annual symmetric percentage change (SPC) of the hippocampal volume as the dependent variable and including an interaction term between NTP and mean PD as the independent variable. The interaction details were examined using the Johnson-Neyman technique and simple slope analysis. The three-way interaction of NTP, mean PD, and time on hippocampal volume was analyzed using a linear mixed-effects model, and the interaction of NTP and time was examined in subgroups divided by the median mean PD. In all models, dropout bias was adjusted by inverse probability weighting.nnRESULTS: The data of 172 participants were analyzed. The qualitative interaction between NTP and mean PD was significant for the annual SPC in the left hippocampus. The regression coefficient of the NTP on annual SPC in the left hippocampus was significantly positive (B=0.038, =.026) at the low-level mean PD (mean-1SD) and significantly negative (B=-0.054, =.001) at the high-level mean PD (mean+1SD). Similar results were obtained in the linear mixed-effects model; the interaction of NTP and time was significant in the higher mean PD group.nnDISCUSSION: In a late middle-aged and older cohort, fewer teeth were associated with a faster rate of left hippocampal atrophy in patients with mild periodontitis, whereas having more teeth was associated with a faster rate of atrophy in those with severe periodontitis. The importance of keeping teeth healthy is suggested.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35502585,

title = {Expression of matrix metalloproteinase-3 and -10 is up-regulated in the periodontal tissues of aged mice},

author = {Yoko Kageyama and Megumi Nakamura and Yohei Igari and Satoshi Yamaguchi and Akiko Oguchi and Yasuhiro Murakawa and Yoshinori Hattori and Yasuyuki Sasano},

doi = {10.1111/jre.12996},

issn = {1600-0765},

year  = {2022},

date = {2022-08-01},

journal = {J Periodontal Res},

volume = {57},

number = {4},

pages = {733--741},

abstract = {OBJECTIVE: The present study was designed to investigate the whole transcriptome of periodontal tissues of both young and aged mice to identify the characteristic up-regulation of protease genes with aging and to localize their translated protein products in the periodontal tissues.nnBACKGROUND: The metzincin protease superfamily is composed of matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases, and a disintegrin and metalloproteinases with thrombospondin motifs. Up-regulation of these extracellular matrix-degrading proteases has been implicated in senescence of tissues and organs, including the skin. However, few studies have investigated the expression profiles of these proteases and potential involvement in aging of periodontal tissues.nnMETHODS: Periodontal tissues with the surrounding mandibular bones were collected from 50- and 10-week-old mice. Total RNA was extracted from the periodontal tissue and analyzed by cap analysis of gene expression (CAGE) to identify differentially expressed genes encoding the metzincin proteases. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to validate the CAGE results, and the phenotypic expression of proteases involved in aging was localized via immunohistochemical analysis.nnRESULTS: The CAGE results showed that the expression levels of MMP-3, -10, and -12 were up-regulated at 50 weeks. Subsequent qRT-PCR analysis showed that the gene expression levels of MMP-3 and -10 were significantly increased with age. MMP-10 immunoreactivity was localized exclusively in the cementum and alveolar bone adjacent to the periodontal ligament and was stronger and broader in aged mice than young mice. MMP-3 immunoreactivity was localized in the periodontal ligaments at both 10 and 50 weeks.nnCONCLUSION: In the present study, we demonstrated that the expression of MMP-3 and -10 increased with aging and identified their characteristic localizations in aged periodontal tissues.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34009675,

title = {Oral health-related quality of life is associated with the prevalence and development of depressive symptoms in older Japanese individuals: The Ohasama Study},

author = {Takashi Ohi and Takahisa Murakami and Takamasa Komiyama and Yoshitada Miyoshi and Kosei Endo and Takako Hiratsuka and Michihiro Satoh and Kei Asayama and Ryusuke Inoue and Masahiro Kikuya and Hirohito Metoki and Atsushi Hozawa and Yutaka Imai and Makoto Watanabe and Takayoshi Ohkubo and Yoshinori Hattori},

doi = {10.1111/ger.12557},

issn = {1741-2358},

year  = {2022},

date = {2022-06-01},

journal = {Gerodontology},

volume = {39},

number = {2},

pages = {204--212},

abstract = {OBJECTIVE: 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.nnBACKGROUND: Previous studies have shown a relationship between poor oral health and depression among older adults; however, findings are inconsistent.nnMATERIALS AND METHODS: Participants were 669 community-dwelling older Japanese individuals aged≥55 years (mean: 67.8 ± 7.2 years). Data of 296 participants were used for longitudinal analyses. OHRQoL was evaluated using the Oral Impacts on Daily Performances scale. Impaired OHRQoL was defined as the presence of at least one impact on the scale. Depressive symptoms were assessed using the Japanese version of the Zung self-rating depression scale with a cut-off score of 40.nnRESULTS: The cross-sectional logistic regression model demonstrated that impaired OHRQoL was significantly associated with depressive symptoms (odds ratio [OR], 5.17; 95% confidence interval [CI], 2.99-8.95) independent of age, sex, body mass index, hypertension, cerebrovascular/cardiovascular disease, smoking, drinking alcohol, education, cognitive function, objective oral health (dentition status) and oral health behaviour (dental visit within 1 year). Similarly, impaired OHRQoL predicted the development of depressive symptoms within 4 years in a fully adjusted longitudinal model (OR, 6.00; 95% CI, 1.38-26.09).nnCONCLUSION: Impaired OHRQoL was identified as a potential comorbidity of depressive symptoms and a predictor for depressive disorder later in life. OHRQoL may be a useful clinical outcome for elder patients with regard to their mental and oral health.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35388479,

title = {Regular dental visits, periodontitis, tooth loss, and atherosclerosis: The Ohasama study},

author = {Sho Yamada and Takamasa Komiyama and Takashi Ohi and Takahisa Murakami and Yoshitada Miyoshi and Kosei Endo and Takako Hiratsuka and Azusa Hara and Michihiro Satoh and Yukako Tatsumi and Ryusuke Inoue and Kei Asayama and Masahiro Kikuya and Atsushi Hozawa and Hirohito Metoki and Yutaka Imai and Takayoshi Ohkubo and Yoshinori Hattori},

doi = {10.1111/jre.12990},

issn = {1600-0765},

year  = {2022},

date = {2022-06-01},

journal = {J Periodontal Res},

volume = {57},

number = {3},

pages = {615--622},

abstract = {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.nnBACKGROUND: Few studies have examined the association between regular dental visits, periodontitis, tooth loss, and atherosclerosis in community dwellers in Japan.nnMETHODS: The participants of this cross-sectional study included community dwellers aged ≥55 years and residing in Ohasama. Exposure variables were regular dental visits; periodontitis, defined as radiographic alveolar bone loss (BL); the Centers for Disease Control/American Academy of Periodontology (CDC/AAP) classification; and number of remaining teeth. The primary outcome was atherosclerosis, defined as maximum carotid intima-media thickness ≥1.1 mm or confirmation of atheromatous plaque.nnRESULTS: Of 602 participants, 117 had atherosclerosis. In the multivariate model, compared to those with regular dental visits, the odds ratio (OR) (95% confidence intervals [CIs]) of atherosclerosis among those with the absence of regular dental visits was 2.16 (1.03-4.49). Regarding BL-max, compared with those in the first quartile, ORs (95% CIs) of those in the second, third, and fourth quartiles were 1.15 (0.65-2.30), 0.65 (0.32-1.35), and 1.57 (0.81-3.01), respectively. Regarding CDC/AAP classification, compared to those with no or mild periodontitis, ORs (95% CIs) for those with moderate and severe periodontitis were 2.48 (0.61-10.1) and 4.26 (1.01-17.5), respectively. Regarding the number of remaining teeth, compared to those with ≥20 teeth, ORs (95%CIs) for those with 10-19 and 1-9 teeth were 1.77 (1.004-3.12) and 0.96 (0.52-1.80), respectively.nnCONCLUSION: The absence of regular dental visits and presence of periodontitis are associated with atherosclerosis among community dwellers in Japan.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35013438,

title = {Relationship between maximum occlusal force and gastrointestinal cancer in community-dwelling older Japanese adults},

author = {Takamasa Komiyama and Takashi Ohi and Wakana Ito and Yoshitada Miyoshi and Takako Hiratsuka and Sanae Matsuyama and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1038/s41598-021-04158-y},

issn = {2045-2322},

year  = {2022},

date = {2022-01-01},

journal = {Sci Rep},

volume = {12},

number = {1},

pages = {440},

abstract = {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. The exposure variables were the number of remaining teeth and the maximum occlusal force, with the outcome being the incidence of gastrointestinal cancer. Covariates were age, sex, medical history, smoking, alcohol consumption, educational attainment, and physical function. The Cox proportional hazard model was used to examine the relationship between the number of remaining teeth, maximum occlusal force, and incidence of gastrointestinal cancer. With a median follow-up of 7.6 years, 63 participants were confirmed to have gastrointestinal cancer. The risk of gastrointestinal cancer was significantly higher in those with an occlusal force lower than the median (hazard ratio, 2.80; 95% confidence interval, 1.54-5.10). No significant risk difference was found according to the number of remaining teeth. Low maximum occlusal force was associated with the incidence of gastrointestinal cancer in community-dwelling older Japanese adults.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33116029,

title = {Multivariate analysis reveals oral health-related quality of life of complete denture wearers with denture adhesives: a multicenter randomized controlled trial},

author = {Yoshihiko Ito and Guang Hong and Akito Tsuboi and Yasuhiko Kawai and Hisatomo Kondo and Taro Nomura and Suguru Kimoto and Atsuko Gunji and Asako Suzuki and Gaku Ohwada and Shunsuke Minakuchi and Yusuke Sato and Tetsuya Suzuki and Katsuhiko Kimoto and Noriyuki Hoshi and Makiko Saita and Yoshikazu Yoneyama and Yohei Sato and Masakazu Morokuma and Joji Okazaki and Takeshi Maeda and Kenichiro Nakai and Tetsuo Ichikawa and Kan Nagao and Keiko Fujimoto and Hiroshi Murata and Tadafumi Kurogi and Kazuma Takase and Masahiro Nishimura and Yasuhiro Nishi and Mamoru Murakami and Toshio Hosoi and Taizo Hamada},

doi = {10.2186/jpr.JPR_D_20_00132},

issn = {2212-4632},

year  = {2021},

date = {2021-08-01},

journal = {J Prosthodont Res},

volume = {65},

number = {3},

pages = {353--359},

abstract = {Purpose To investigate the difference in improvement of oral health-related quality of life (OHR-QoL) depending on the oral and denture conditions of a complete denture wearer when using a cream or powder type denture adhesive in a 10-center parallel randomized clinical trial.Methods Two hundred edentulous subjects who wore complete dentures were allocated to each of the three groups according to denture adhesive type: cream, powder, and control (saline solution). The materials were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention were collected. OHR-QoL was assessed using the Japanese version of the modified Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT-J) scale for outcome. Multivariate analysis was used to investigate improvements in OHR-QoL according to participant characteristics among complete denture wearers using these materials.Results OHIP-EDENT-J scores were significantly decreased in all groups after the intervention (p < 0.05); however, there were no statistically significant differences among the groups. Multiple logistic regression analysis revealed a significant association between the vertical height of the maxillary and mandibular alveolar ridge and OHIP-EDENT-J scores in the cream-type denture adhesive group. In contrast, there were no significant association between participant characteristics and OHIP-EDENT-J scores in the powder-type adhesive and control groups.Conclusions The use of denture adhesives could improve OHR-QoL for complete denture wearers. The cream-type denture adhesives may be expected to improve OHR-QoL in patients with poor residual ridge conditions compared with patients with good residual ridge conditions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33587891,

title = {Relationship Between Oral Health and Fractures in Community-Dwelling Older Japanese Adults},

author = {Wakana Ito and Takamasa Komiyama and Takashi Ohi and Takako Hiratsuka and Sanae Matsuyama and Toshimasa Sone and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1016/j.jamda.2021.01.058},

issn = {1538-9375},

year  = {2021},

date = {2021-06-01},

journal = {J Am Med Dir Assoc},

volume = {22},

number = {6},

pages = {1184--1189.e1},

abstract = {OBJECTIVE: To investigate the relationship between poor oral health and the incidence of fall-related fractures in older Japanese individuals.nnDESIGN: A 9-year prospective cohort study.nnSETTING AND PARTICIPANTS: Participants comprised 937 community-dwelling older Japanese adults aged 70 years or older. They all lived in the Tsurugaya district, a suburban area of Sendai city, and underwent comprehensive geriatric assessment, including an oral examination, in a public facility.nnMEASUREMENTS: The exposure variables were related to oral health status (posterior occlusal support, number of remaining teeth, and occlusal force). The outcome measure was the incidence of fall-related fractures, which was determined by National Health Insurance data. Analyzed covariates included age, sex, medical history, smoking, alcohol drinking, educational level, depressive symptoms, cognitive impairment, physical function, body mass index, and history of falls. Statistical relationships were examined by calculating hazard ratios (HRs) at 95% confidence intervals (CIs) using the Cox proportional hazard model.nnRESULTS: In the multivariate analysis, the HRs of fall-related fractures were significantly higher in those with unilateral posterior occlusal support (HR, 2.72; 95% CI, 1.13-6.55) and no posterior occlusal support (HR, 2.58; 95% CI, 1.29-5.15) than in those with bilateral posterior occlusal support. The HRs (95% CIs) of fall-related fractures in individuals with 10-19 and 1-9 teeth and edentulous individuals were 1.77 (0.81-3.89), 2.67 (1.24-5.75), and 2.31 (1.01-5.28), respectively, compared to those with ≥20 teeth.nnCONCLUSIONS AND IMPLICATIONS: Poor oral health status is a risk factor for the incidence of fall-related fractures in community-dwelling older Japanese individuals. The findings suggest that attention should be focused on oral health status to further understand the risk of fall-related fractures among community-dwelling older adults.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33637801,

title = {Statistical parametric mapping of three-dimensional local activity distribution of skeletal muscle using magnetic resonance imaging (MRI)},

author = {Satoshi Yamaguchi and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1038/s41598-021-84247-0},

issn = {2045-2322},

year  = {2021},

date = {2021-02-01},

urldate = {2021-02-01},

journal = {Sci Rep},

volume = {11},

number = {1},

pages = {4808},

abstract = {Analysis of the internal local activity distribution in human skeletal muscles is important for managing muscle fatigue/pain and dysfunction. However, no method is established for three-dimensional (3D) statistical analysis of features of activity regions common to multiple subjects during voluntary motor tasks. We investigated the characteristics of muscle activity distribution from the data of ten healthy subjects (29 ± 1 year old, 2 women) during voluntary teeth clenching under two different occlusal conditions by applying spatial normalization and statistical parametric mapping (SPM) to analysis of muscle functional magnetic resonance imaging (mfMRI) using increase in transverse relaxation time (T2) of the skeletal muscle induced by exercise. The expansion of areas with significant T2 increase was observed in the masticatory muscles after clenching with molar loss comparing with intact dentition. The muscle activity distribution characteristics common to a group of subjects, i.e., the active region in the temporal muscle ipsilateral to the side with the molar loss and medial pterygoid muscle contralateral to the side with the molar loss, were clarified in 3D by applying spatial normalization and SPM to mfMRI analysis. This method might elucidate the functional distribution within the muscles and the localized muscular activity related to skeletal muscle disorders.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33086434,

title = {Caregiver-reported dementia as a predictor of oral health among patients receiving home-visit dental treatment: A retrospective cohort study},

author = {Satoshi Yamaguchi and Yukari Horigome and Kosei Endo and Moritoshi Komagata and Shinya Komai and Kenichiro Komaki and Hideki Miyata and Kazuhiko Sugano and Setsuko Ito and Shiho Itabashi and Harumi Sato and Minako Okahashi and Sayaka Kishi and Rika Abe and Yoshinori Hattori},

doi = {10.1002/cre2.333},

issn = {2057-4347},

year  = {2021},

date = {2021-02-01},

journal = {Clin Exp Dent Res},

volume = {7},

number = {1},

pages = {49--55},

abstract = {OBJECTIVE: To assess caregiver-reported dementia as a risk factor for retained roots, an indicator of poor oral hygiene, among patients receiving home-visit dental treatment in Japan.nnMETHODS: The medical records of 231 dentate patients who received home-visit dental treatment (covered by public medical insurance) for more than 2 years were retrospectively analyzed. The number of teeth and retained roots at the initial and final examinations were obtained from the dental charts, and the "change in the number of retained roots from initial to final examination" was determined. The presence or absence of caregiver-reported dementia, diabetes, and osteoporosis, as well as the level of long-term care needed, were used as indicators of general health condition at the initial interview. Multiple regression analyses were conducted in five models that tested the association of independent variables (age, gender, observation period, general health, presence or absence of caregiver-reported dementia at the initial interview) with changes in the number of retained roots.nnRESULTS: In all models, the presence of caregiver-reported dementia at the initial interview was significantly associated with the change in the number of retained roots (p < .05). The adjusted coefficient of determination (R ) of model 5, which included all the predetermined independent factors, was .168.nnCONCLUSIONS: Caregiver-reported dementia may be a risk factor for an increase in the number of retained roots among patients who receive home-visit dental treatment and may serve as an indicator of the need for regular and proactive oral hygiene management.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33563875,

title = {Expression of tartrate-resistant acid phosphatase and cathepsin K during osteoclast differentiation in developing mouse mandibles},

author = {Megumi Nakamura and Naoki Aoyama and Satoshi Yamaguchi and Yasuyuki Sasano},

doi = {10.2220/biomedres.42.13},

issn = {1880-313X},

year  = {2021},

date = {2021-01-01},

journal = {Biomed Res},

volume = {42},

number = {1},

pages = {13--21},

abstract = {The present study was designed to test the hypothesis that osteoclasts appear after or at the same time as the initiation of bone mineralization in developing intramembranous bones. We examined mineral deposition via Von Kossa staining to determine when bone mineralization begins, tartrate-resistant acid phosphatase (TRAP) activity and cathepsin K immunoreactivity to identify the presence of osteoclasts, and their mRNA expression levels to assess osteoclastic differentiation in the embryonic mouse mandible. Cathepsin K-immunopositive cells were detected around the same time as the onset of bone mineralization, whereas TRAP-positive cells appeared prior to bone mineralization. Cathepsin K protein was expressed only in multinucleated osteoclasts, whereas TRAP activity was identified in both mono- and multinucleated cells. During bone development, TRAP-positive cells altered their morphology, which was related to the number of their nuclei. The elevated mRNA levels of TRAP and cathepsin K were consistent with the increased percentage of multinucleated osteoclasts and the progression of bone development. Our study revealed that TRAP-positive cells appear prior to bone mineralization, and TRAP- and cathepsin K-positive multinucleated osteoclasts appear at the same time as the initiation of bone mineralization in embryonic mouse mandibles, suggesting that osteoclasts contribute to bone matrix maturation during intramembranous ossification.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33162454,

title = {The Association between Number of Remaining Teeth and Maintenance of Successful Aging in Japanese Older People: A 9-Year Longitudinal Study},

author = {Fumiya Tanji and Takamasa Komiyama and Takashi Ohi and Yoshinori Hattori and Makoto Watanabe and Yukai Lu and Ichiro Tsuji},

doi = {10.1620/tjem.252.245},

issn = {1349-3329},

year  = {2020},

date = {2020-11-01},

journal = {Tohoku J Exp Med},

volume = {252},

number = {3},

pages = {245--252},

abstract = {With population aging, an increasing attention has been paid to quality of life rather than mere longevity. Now, it is urgently needed to clarify predictors of well-being in later life, i.e., "successful aging (SA)." The aim of this study is to investigate whether the number of remaining teeth impacts on maintenance of SA among Japanese older people. The present study was conducted in Tsurugaya district, a suburban area of Sendai, in northern Japan, and included older people aged ≥ 70 years who had met the criteria for SA at a 2003 baseline survey. At the baseline survey, dentists obtained data for the number of remaining teeth. We obtained information about Long-term Care Insurance certification, including the dates of incident functional disability and death between 2003 and 2012. Data pertaining to health-related quality of life (HRQOL) were collected at the 2003 baseline survey and the 2012 follow-up survey. Maintenance of SA was defined in terms of survival, disability-free status and high HRQOL in both 2003 and 2012. Among 450 participants, 108 (24.0%) were considered to have maintained a state of SA. When participants were classified into three groups according to previous studies, in comparison with participants who retained 0-9 teeth, the multivariate prevalence ratios (95% confidence intervals) were 1.39 (0.81-2.36) for those who retained 10-19 teeth and 1.58 (1.002-2.50) for those who retained ≥ 20 teeth (p trend = 0.046). The present results suggest that retaining ≥ 20 teeth is associated with maintenance of SA among Japanese older people.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31548479,

title = {Correlation between Changes in the Transverse Relaxation Time and Electromyographic Measurements of the Superficial Masseter and Temporal Muscles},

author = {Tsuyoshi Fujii and Satoshi Yamaguchi and Yul-Wan Sung and Makoto Watanabe and Yoshinori Hattori},

doi = {10.2463/mrms.tn.2019-0035},

issn = {1880-2206},

year  = {2020},

date = {2020-08-01},

journal = {Magn Reson Med Sci},

volume = {19},

number = {3},

pages = {268--275},

abstract = {We analyzed the correlations between the T shift and integrated electromyographic (iEMG) values in the masseter and temporal muscles. Six healthy adults engaged in a clenching task over two durations at various bite forces. We evaluated the mean T shift per voxel and assessed their correlations with iEMG using a linear mixed model. The regression coefficients were different for each muscle type, similar for the left and right sides, and decreased upon doubling duration.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32428306,

title = {Verification of the criteria for reduced occlusal force to diagnose oral hypofunction in older Japanese people: A prospective cohort study on incident functional disability},

author = {Takamasa Komiyama and Takashi Ohi and Yoshitada Miyoshi and Yasutake Tomata and Shu Zhang and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1111/joor.13021},

issn = {1365-2842},

year  = {2020},

date = {2020-08-01},

journal = {J Oral Rehabil},

volume = {47},

number = {8},

pages = {989--997},

abstract = {In 2016, the Japanese Society of Gerodontology (JSG) proposed the concept of "oral hypofunction (OHF)," and recommended two initial criteria for reduced occlusal force (ROF): <200 N of maximum occlusal force (MOF) and < 20 remaining teeth. However, the JSG stated that these criteria need to be reviewed by accumulating further evidence. To examine the validity and equivalence of the two criteria for ROF in the diagnostic criteria for OHF by using the incidence of functional disability as the outcome. This study enrolled 815 community-dwelling Japanese individuals ≥ 70 years. They underwent examinations for physical, mental and social functions; MOF; and number of teeth at baseline. The incidence of functional disability (a condition that requires at least partial assistance with daily activities) based on the first certification of long-term care insurance was followed up. The Cox proportional hazard model revealed that MOF < 200 N (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.04-1.72) and < 20 teeth (HR, 1.40; 95% CI, 1.07-1.84) were significantly associated with increased risk of functional disability. Receiver operating characteristic curve analyses revealed that the optimal cut-off values of MOF and number of teeth that best predicted incident functional disability were 264.6 N and 19 teeth, respectively. Twelve teeth were the optimal threshold that best predicted < 200 N of MOF. The two criteria for ROF in the diagnostic criteria for OHF had some degree of validity. However, further studies are needed to develop appropriate and reliable criteria for a decision of ROF.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32522688,

title = {Cognitive impairment and depressive symptoms lead to biases in self-evaluated masticatory performance among community-dwelling older Japanese adults: the Tsurugaya Project},

author = {Takamasa Komiyama and Takashi Ohi and Takako Hiratsuka and Yoshitada Miyoshi and Yasutake Tomata and Shu Zhang and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1016/j.jdent.2020.103403},

issn = {1879-176X},

year  = {2020},

date = {2020-08-01},

journal = {J Dent},

volume = {99},

pages = {103403},

abstract = {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.nnMETHODS: 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. Self-evaluated masticatory performance (SMP) was assessed for 10 food items. Measured masticatory performance (MMP) was assessed as the maximum occlusal force, which is a surrogate indicator. Multivariate logistic regression was applied to examine the associations of cognitive impairment, depressive symptoms, and their combination with the deviation between SMP and MMP, SMP overestimation, and SMP underestimation, with adjustment for age, sex, body mass index, smoking, alcohol consumption, duration of education, medical history, physical function, regular dental visits, and number of teeth.nnRESULTS: Cognitive impairment was significantly associated with SMP overestimation (odds ratio [OR]: 2.37, 95% confidence interval [CI]: 1.25-4.50); in parallel, SMP underestimation was significantly associated with depressive symptoms (OR: 1.86, 95% CI: 1.14-3.04) and the presence of both cognitive impairment and depressive symptoms (OR: 2.77, 95% CI: 1.01-7.61).nnCONCLUSIONS: This cross-sectional study clarifies the gap between self-evaluated and measured masticatory performance in geriatric participants who have cognitive impairment or depressive symptoms. These biases must be taken into consideration when appraising self-evaluated masticatory performance or oral health status in geriatric patients with cognitive impairment or depressive symptoms.nnCLINICAL SIGNIFICANCE: This study explores the biases in geriatric patients with cognitive impairment or symptoms of depression. It clarifies that participants with cognitive impairment tend to overestimate their self-evaluated masticatory performance. Conversely, the participants with depression symptoms tend to underestimate their self-evaluated masticatory performance.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31494054,

title = {The association between bilateral maximum occlusal force and all-cause mortality among community-dwelling older adults: The Tsurugaya project},

author = {Takashi Ohi and Takamasa Komiyama and Yoshitada Miyoshi and Takahisa Murakami and Akito Tsuboi and Yasutake Tomata and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1016/j.jpor.2019.08.005},

issn = {2212-4632},

year  = {2020},

date = {2020-07-01},

journal = {J Prosthodont Res},

volume = {64},

number = {3},

pages = {289--295},

abstract = {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.nnMETHODS: 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 ± 4.5 years). Bilateral MOF in the intercuspal position was recorded with horseshoe-shaped pressure-sensitive film. Participants were grouped by gender into tertiles according to MOF. Demographic variables, chronicity, comorbidity, physical status, cognitive and psychological status, social functioning, and blood chemistry data were also assessed. Information regarding all-cause mortality and migration was obtained from the Sendai Municipal Authority. Cox proportional hazard modeling was performed to assess all-cause mortality during the follow-up period.nnRESULTS: In total, 159 male and 109 female participants died over a median 12.9-year follow-up period, and the cumulative mortality significantly increased with lower MOF in both males and females. The multivariate Cox proportional hazard model demonstrated a significant increase in the risk of all-cause mortality associated with lower tertiles of MOF, relative to the upper tertile in males (hazard ratio: 1.62; 95% confidence interval: 1.05-2.51) and females (hazard ratio: 1.94; 95% confidence interval: 1.10-3.56).nnCONCLUSIONS: There was a significant and independent association of bilateral MOF with all-cause mortality in community-dwelling elderly males and females in Japan. These findings suggested that maintenance of oral functioning contributes to general health.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31501069,

title = {Effect of denture adhesives on oral moisture: A multicenter randomized controlled trial},

author = {Yasuhiro Nishi and Taro Nomura and Mamoru Murakami and Yasuhiko Kawai and Masahiro Nishimura and Hisatomo Kondo and Yoshihiko Ito and Akito Tsuboi and Guang Hong and Suguru Kimoto and Atsuko Gunji and Asako Suzuki and Gaku Ohwada and Shunsuke Minakuchi and Yusuke Sato and Tetsuya Suzuki and Katsuhiko Kimoto and Noriyuki Hoshi and Makiko Saita and Yoshikazu Yoneyama and Yohei Sato and Masakazu Morokuma and Joji Okazaki and Takeshi Maeda and Kenichiro Nakai and Tetsuo Ichikawa and Kan Nagao and Keiko Fujimoto and Hiroshi Murata and Tadafumi Kurogi and Kazuhiro Yoshida and Toshio Hosoi and Taizo Hamada},

doi = {10.1016/j.jpor.2019.08.004},

issn = {2212-4632},

year  = {2020},

date = {2020-07-01},

journal = {J Prosthodont Res},

volume = {64},

number = {3},

pages = {281--288},

abstract = {PURPOSE: The purpose of this study was to investigate the effect of denture adhesives on oral moisture in a 10-center parallel randomized clinical trial.nnMETHODS: Two hundred edentulous subjects wearing complete dentures were allocated into three groups: cream-type adhesive, powder-type adhesive and control groups. The adhesives (and saline solution in the control group) were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention for eight meals over 4 days were obtained. For the main outcome, oral moisture was measured with a moisture checking device. Secondary outcomes were denture satisfaction, masticatory performance, denture retention, and occlusal force. In addition to between-group and within-group comparisons of oral moisture, investigations for secondary outcomes were undertaken in subgroups classified according to the degree of oral moisture at baseline (normal subgroup and dry mouth subgroup). Intention-to-treat analysis was also performed.nnRESULTS: Between-group and within-group comparisons of oral moisture showed no significant differences. The cream-type and powder-type denture adhesives were significantly effective in the dry mouth group for denture satisfaction ratings of ability to masticate, stability, retention, and comfort of mandibular dentures (p<0.05). The masticatory performance and retentive force of the dry mouth denture adhesive using groups were significantly improved after intervention (p<0.05).nnCONCLUSIONS: The oral moisture of complete denture wearers was not influenced by the use of denture adhesives. Our findings showed that denture adhesives improved subjective denture satisfaction, masticatory performance, and retention for complete denture patients with oral dryness.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31485781,

title = {Contribution of systemic inflammation and nutritional status to the relationship between tooth loss and mortality in a community-dwelling older Japanese population: a mediation analysis of data from the Tsurugaya project},

author = {Takako Hiratsuka and Takamasa Komiyama and Takashi Ohi and Fumiya Tanji and Yasutake Tomata and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1007/s00784-019-03072-y},

issn = {1436-3771},

year  = {2020},

date = {2020-06-01},

journal = {Clin Oral Investig},

volume = {24},

number = {6},

pages = {2071--2077},

abstract = {OBJECTIVES: To assess whether systemic inflammation and nutritional status contribute to a relationship between tooth loss and mortality in community-dwelling older Japanese individuals using mediation analyses.nnMATERIALS AND METHODS: This longitudinal study targeted community-dwelling older Japanese individuals (N = 891). The exposure variable was the number of teeth (edentulous, 1-9, 10-19, ≥ 20), while the outcome was all-cause mortality from 2003 to 2016. Nutritional status and systemic inflammation were evaluated as mediators and based on serum albumin and high-sensitivity C-reactive protein levels, respectively. Covariates included age, sex, smoking, alcohol consumption, medical history, educational level, depressive symptoms, cognitive impairment, and physical function. The Cox proportional hazards model was applied to calculate hazard ratios (HRs) for the association between tooth loss and mortality and the contributions of systemic inflammation and nutritional status to this association.nnRESULTS: Edentulous participants (HR, 1.84; 95 % confidence interval [CI], 1.30-2.59) and those with 1-9 teeth (HR, 1.75; 95% CI, 1.28-2.40) groups exhibited a significantly higher risk of mortality than did those with ≥ 20 teeth. Mediation analyses showed that nutritional status contributed to the association between tooth loss and mortality in participants with 1-9 teeth, whereas systemic inflammation played no role in this association.nnCONCLUSIONS: Nutritional status may contribute to the association between tooth loss and mortality in community-dwelling older Japanese individuals with fewer remaining teeth.nnCLINICAL RELEVANCE: The data from this prospective cohort study help in elucidating parts of the biological mechanism underlying tooth loss and all-cause mortality in older individuals.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30686817,

title = {Dental Status is Associated With Incident Functional Disability in Community-Dwelling Older Japanese: A Prospective Cohort Study Using Propensity Score Matching},

author = {Takamasa Komiyama and Takashi Ohi and Yasutake Tomata and Fumiya Tanji and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.2188/jea.JE20180203},

issn = {1349-9092},

year  = {2020},

date = {2020-02-01},

journal = {J Epidemiol},

volume = {30},

number = {2},

pages = {84--90},

abstract = {BACKGROUND: A growing number of epidemiology studies have shown that poor oral health is associated with an increased incidence of functional disability. However, there are few studies in which the confounding bias is adjusted appropriately. In this study, we examined whether dental status is associated with functional disability in elderly Japanese using a 13-year prospective cohort study after elimination of confounding factors with propensity score matching.nnMETHODS: Participants were community-dwelling Japanese aged 70 years or older who lived in the Tsurugaya district of Sendai (n = 838). The number of remaining teeth (over 20 teeth vs 0-19 teeth) was defined as the exposure variable. The outcome was the incidence of functional disability, defined as the first certification of long-term care insurance (LTCI) in Japan. The variables that were used to determine propensity score matching were age, sex, body mass index (BMI), medical history (stroke, hypertension, myocardial infarction, cancer, and diabetes), smoking, alcohol consumption, educational attainment, depression symptoms, cognitive impairment, physical function, social support, and marital status.nnRESULTS: As a result of the propensity score matching, 574 participants were selected. Participants with 0-19 teeth were more likely to develop functional disability than those with 20 or more teeth (hazard ratio 1.33; 95% confidence interval, 1.01-1.75).nnCONCLUSIONS: In this prospective cohort study targeting community-dwelling older adults in Japan, having less than 20 teeth was confirmed to be an independent risk factor for functional disability even after conducting propensity score matching. This study supports previous publications showing that oral health is associated with functional disability.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30975019,

title = {Subjective Evaluation of Denture Adhesives: A Multicenter Randomized Controlled Trial},

author = {G Ohwada and S Minakuchi and Y Sato and H Kondo and T Nomura and A Tsuboi and G Hong and Y Itoh and Y Kawai and S Kimoto and A Gunji and A Suzuki and T Suzuki and K Kimoto and N Hoshi and M Saita and Y Yoneyama and Y Sato and M Morokuma and J Okazaki and T Maeda and K Nakai and T Ichikawa and K Nagao and K Fujimoto and H Murata and T Kurogi and K Yoshida and M Nishimura and Y Nishi and M Murakami and T Hosoi and T Hamada},

doi = {10.1177/2380084419837607},

issn = {2380-0852},

year  = {2020},

date = {2020-01-01},

journal = {JDR Clin Trans Res},

volume = {5},

number = {1},

pages = {50--61},

abstract = {INTRODUCTION: Many reports show that denture adhesives improve the retention and stability of dentures. However, few randomized controlled trials have examined the effects of denture adhesives.nnOBJECTIVE: This 10-center randomized controlled trial with parallel groups involving 200 edentulous patients wearing complete dentures aimed to evaluate the effects of short-term use of cream and powder denture adhesives.nnMETHODS: Patients were allocated into 2 cream- and powder-type adhesive groups and 1 control group. Intervention groups were treated with the 2 adhesives (1 each), and the control group received saline solution. Adhesive or control was applied to the denture-mucosal surface for 4 d, and data at baseline and after day 4 of intervention (i.e., 8 meals) were obtained. Patient satisfaction was evaluated with a 100-mm visual analog scale. Oral health-related quality of life was measured with the Japanese version of the Oral Health Impact Profile for Edentulous Patients. Perceived chewing ability was evaluated by a questionnaire regarding ease of chewing and swallowing food. Between-group comparisons were performed with Kruskal-Wallis tests with the Mann-Whitney  test adjusted by Bonferroni correction. Within-group comparisons of pre- and postintervention measurements were performed with the Wilcoxon signed-rank test. Intention-to-treat analysis was also performed.nnRESULTS: Between-group comparisons showed no significant differences for general satisfaction or Oral Health Impact Profile for Edentulous Patients. However, significant differences in satisfaction with various denture functions with cream- and powder-type adhesives were seen in pre- and postintervention comparisons ( < 0.05). Significant differences were also observed for perceived chewing ability of hard foods ( < 0.05).nnCONCLUSION: These results suggest that although denture adhesives do not invariably improve denture function, they do affect subjective evaluations and possibly chewing of hard foods. Therefore, the effects of denture adhesive use are insufficient to resolve any fundamental dissatisfaction with dentures ( ClinicalTrials.gov NCT01712802 ).nnKNOWLEDGE TRANSFER STATEMENT: The results of this study suggest that denture adhesives should be applied under certain conditions; however, an appropriate diagnosis is important before application. These practice-based data provide information to establish evidence-based guidelines for applying denture adhesives.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30868597,

title = {Preliminary exploration for evaluating acuity of oral texture perception},

author = {Nao Furukawa and Yoshihiko Ito and Yasue Tanaka and Wakana Ito and Yoshinori Hattori},

doi = {10.1111/jtxs.12400},

issn = {1745-4603},

year  = {2019},

date = {2019-06-01},

journal = {J Texture Stud},

volume = {50},

number = {3},

pages = {217--223},

abstract = {Despite the important role of oral texture perception in feeding and nutritional homeostasis, its impairment has not been of particular clinical interest, and no clinical protocol is available to evaluate its acuity. This preliminary study aimed to establish a method to evaluate the acuity of oral texture perception. Because texture perception is regarded as reflecting integrity of the sensorimotor system of the jaw and mouth, we hypothesized that the ability to perceive various aspects of food texture would correlate with each other, and tested our hypothesis in 11 healthy adults. First, we prepared three types of test foods with different dominant textures, each of which comprised a series of stimuli with different ingredient concentrations; we used these test foods in discrimination tests involving pairwise comparison. Tests performed using the up-down staircase method revealed significant correlation among the discrimination thresholds for three test foods, suggesting that acuities of texture perception correlated with each other across different textural attributes. Second, we examined the associations between the acuity of texture perception and some aspects of mechanical sensation of the tongue: tactile and two-point discrimination thresholds, as well as the graininess recognition threshold. The acuity of texture perception of the subjects whose sensitivity was low for at least one of these aspects of mechanical sensation (n = 5) was significantly lower than that exhibited by the other subjects (Wilcoxon rank-sum test, p = 0.0417). We concluded that oral texture perception ability can be evaluated by discrimination tests for specific aspects of texture, using appropriate test foods.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29880334,

title = {Relationship between status of dentition and incident functional disability in an elderly Japanese population: prospective cohort study of the Tsurugaya project},

author = {Takamasa Komiyama and Takashi Ohi and Yoshitada Miyoshi and Takahisa Murakami and Akito Tsuboi and Yasutake Tomata and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1016/j.jpor.2018.04.003},

issn = {2212-4632},

year  = {2018},

date = {2018-10-01},

journal = {J Prosthodont Res},

volume = {62},

number = {4},

pages = {443--448},

abstract = {PURPOSE: The purpose of this study was to examine whether the status of dentition is associated with incident functional disability in elderly people.nnMETHODS: 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. Incident functional disability was defined by the first certification of long-term care insurance in Japan. Data regarding age, sex, body mass index, medical history, smoking, alcohol consumption, education, depressive symptoms, cognitive impairment, social support, history of fall, and subjective masticatory ability were collected.nnRESULTS: During follow-up for 5185 person-years, 305 participants experienced functional disability. Considering the follow-up data of  ≥3 years from baseline, participants in Zones C (hazard ratio [HR], 1.98; 95 % confidence interval [CI], 1.26-3.11) and D (HR, 2.50; 95 %CI, 1.54-4.05) were found to be more likely to develop functional disability than those in Zone A (p for trend=0.002).nnCONCLUSIONS: Status of dentition was associated with incident functional disability in an elderly Japanese population. The findings of this study suggest that maintenance of remaining teeth and retention of occlusal supports contribute to the prevention of functional disability.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30126407,

title = {Association between tooth loss and cognitive impairment in community-dwelling older Japanese adults: a 4-year prospective cohort study from the Ohasama study},

author = {Sho Saito and Takashi Ohi and Takahisa Murakami and Takamasa Komiyama and Yoshitada Miyoshi and Kosei Endo and Michihiro Satoh and Kei Asayama and Ryusuke Inoue and Masahiro Kikuya and Hirohito Metoki and Yutaka Imai and Takayoshi Ohkubo and Yoshinori Hattori},

doi = {10.1186/s12903-018-0602-7},

issn = {1472-6831},

year  = {2018},

date = {2018-08-01},

journal = {BMC Oral Health},

volume = {18},

number = {1},

pages = {142},

abstract = {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.nnMETHODS: This 4-year prospective cohort study followed 140 older adults (69.3% female) without cognitive impairment aged ≥65 years (mean age: 70.9 ± 4.3 years) living in the town of Ohasama, Iwate Prefecture, Japan. Cognitive function was evaluated with the Mini-Mental State Examination (MMSE) in baseline and follow-up surveys. Based on a baseline oral examination, the participants were divided into those with 0-9 teeth and those with ≥10 teeth. To investigate the association between tooth loss and cognitive impairment, we applied a multiple logistic regression analysis adjusted for age, sex, hypertension, diabetes, cerebrovascular/cardiovascular disease, hypercholesterolemia, depressive symptoms, body mass index, smoking status, drinking status, duration of education, and baseline MMSE score.nnRESULTS: In the 4 years after the baseline survey, 27 participants (19.3%) developed cognitive impairment (i.e., MMSE scores of ≤24). Multiple logistic regression analysis indicated that participants with 0-9 teeth were more likely to develop cognitive impairment than those with ≥10 teeth were (odds ratio: 3.31; 95% confidence interval: 1.07-10.2). Age, male gender, and baseline MMSE scores were also significantly associated with cognitive impairment.nnCONCLUSIONS: Tooth loss was independently associated with the development of cognitive impairment within 4 years among community-dwelling older adults. This finding corroborates the hypothesis that tooth loss may be a predictor or risk factor for cognitive decline.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30931768,

title = {Maximum Occlusal Force and Incident Functional Disability in Older Adults: The Tsurugaya Project},

author = {T Ohi and T Komiyama and Y Miyoshi and T Murakami and A Tsuboi and Y Tomata and I Tsuji and M Watanabe and Y Hattori},

doi = {10.1177/2380084418761329},

issn = {2380-0852},

year  = {2018},

date = {2018-04-01},

journal = {JDR Clin Trans Res},

volume = {3},

number = {2},

pages = {195--202},

abstract = {The purpose of the current study was to investigate the association between maximum occlusal force, which is an objective predictor of masticatory performance, and incident functional disability in an elderly Japanese population. A prospective cohort study was conducted targeting 815 (51.7% female) community-dwelling older adults aged ≥70 y residing in the Tsurugaya district, Sendai, Japan. The outcome measurement was incident functional disability, defined as a first certification of long-term care insurance in Japan, which is determined on the basis of a strictly established, uniform, nationwide standard. During a median follow-up of 7.9 y (interquartile range, 4.8-7.9 y), information on long-term care insurance was obtained from the Sendai Municipal Authority. Bilateral maximum occlusal forces of the participants were measured using a horseshoe-shaped pressure-indicating film, and the participants were categorized into quartiles based on occlusal force. Adjusted hazard ratios for functional disability were estimated with Cox proportional hazard models, adjusted for age, sex, body mass index, medical history, smoking status, alcohol consumption, duration of education, depressive symptoms, cognitive impairment, physical functioning, marital status, history of falls, and number of remaining teeth. The multiple-adjusted hazard ratios and 95% confidence intervals (CIs) for incident functional disability compared to the greatest occlusal force quartile were 1.53 (95% CI, 1.02-2.33), 1.64 (95% CI, 1.06-2.55), and 1.64 (95% CI, 1.01-2.68) for the third, second, and first quartiles, respectively ( P for trend = 0.011). A lower maximum occlusal force was significantly associated with an increased risk of functional disability independently of possible confounders, including the number of remaining teeth. Occlusal force may be a useful indicator of the relationship between oral function and geriatric health. Knowledge Transfer Statement:This prospective cohort study demonstrated that lower maximum occlusal force was associated with an increased risk of functional disability in older adults, even after adjustment for possible confounding factors, including the number of remaining teeth. This strengthens the rationale regarding the association between oral function and geriatric health. Particularly in older adults, occlusal force is reduced by several factors other than tooth loss, such as the absence of a dental prostheses, sarcopenia in the masticatory muscle, poor periodontal condition, and orofacial pain. Our findings suggest that maximum occlusal force may be a useful biomarker associated with diverse parameters aside from the number of remaining teeth.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29090477,

title = {Analysis of masticatory muscle coordination during unilateral single-tooth clenching using muscle functional magnetic resonance imaging},

author = {S Yamaguchi and C Okada and Y Watanabe and M Watanabe and Y Hattori},

doi = {10.1111/joor.12583},

issn = {1365-2842},

year  = {2018},

date = {2018-01-01},

journal = {J Oral Rehabil},

volume = {45},

number = {1},

pages = {9--16},

abstract = {In a previous study, we used muscle functional magnetic resonance imaging to show that the anterior movement of the occlusal point increased the activity of the superior head of the ipsilateral lateral pterygoid muscle (ipsilateral SHLP) during unilateral single-tooth clenching. The purpose of this study was to verify the hypothesis that the increased activity of the ipsilateral SHLP described above serves to antagonise the occlusal force acting on the condyle. In total, 9 healthy volunteers were requested to perform left unilateral clenching at the first molar or first premolar region for 1 minute at 20% or 40% maximum voluntary clenching force. Changes in the mean proton transverse relaxation time (∆T2) were examined from the magnetic resonance images obtained before and after each clenching act as an index of the activity in all masticatory muscles. Correlation analyses of the mean ΔT2 for each volume of interest were performed with the first molar or premolar clenches to analyse the correlation between the activities in each muscle. A statistically significant correlation was exhibited between the ipsilateral temporal and ipsilateral SHLP (r = .651, P = .003) during first premolar clenching. However, no significant correlations were observed in the ipsilateral SHLP during first molar clenching. The results of this study suggest that the ipsilateral SHLP may contribute to the pulling of the mandibular condyle forward against the occlusal force generated by the ipsilateral temporal muscle.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30538450,

title = {Initial osteoblast adhesion and subsequent differentiation on zirconia surfaces are regulated by integrins and heparin-sensitive molecule},

author = {Feng Luo and Guang Hong and Hiroyuki Matsui and Kosei Endo and Qianbing Wan and Keiichi Sasaki},

doi = {10.2147/IJN.S175536},

issn = {1178-2013},

year  = {2018},

date = {2018-01-01},

journal = {Int J Nanomedicine},

volume = {13},

pages = {7657--7667},

abstract = {PURPOSE: It is well known that zirconia materials have good biocompatibility; however, little is known regarding the mechanism by which cells attach to these materials. The purpose of this study is to elucidate the mechanism of cell attachment.nnMATERIALS AND METHODS: In this study, we examined the surface characteristics of ceria-stabilized zirconia/alumina nanocomposite (NANOZR), yttria-stabilized zirconia (Y-TZP) and commercially pure titanium (CpTi), and we evaluated the initial response of osteoblast-like cells to them with different inhibitors.nnRESULTS: Under the same polishing treatment, the three materials, NANOZR, Y-TZP and CpTi, show similar surface wettability but different surface roughness. Osteoblasts could adhere to the surface of all three materials, and spindle shapes were clearer in serum-containing media compared to PBS and serum-free culture media, suggesting that serum-contained proteins are helpful for the initial cell adhesion and spreading. Cell adhesion and proliferation were disrupted in the presence of EDTA. RGD-peptide interfered with cell proliferation by affecting cell protrusion and stress fibers. Monoclonal antibody against non-RGD type integrin αβ enhanced proliferation in Y-TZP, CpTi and culture dish but not in NANOZR. Cell proliferation on NANOZR was specifically inhibited in the presence of heparin. Furthermore, under heparin administration, spindle shape formation was maintained but actin cytoskeleton was disrupted, resulting in loose cellular spreading.nnCONCLUSION: These results suggest that RGD type integrins and heparin-sensitive protein in coordination regulate cell morphology and proliferation on NANOZR, through the regulation of cell polarity and stress fiber formation, respectively.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28750107,

title = {Practice-Based Longitudinal Study of Multifactorial Risk Assessment for Periodontal Condition and Survival of Remaining Teeth in Patients with Removable Partial Dentures},

author = {Shigeto Koyama and Takeshi Fuji and Takashi Ohi and Kenji Kadowaki and Nobuhiro Yoda and Keiichi Sasaki},

doi = {10.11607/ijp.5173},

issn = {0893-2174},

year  = {2018},

date = {2018-01-01},

journal = {Int J Prosthodont},

volume = {31},

number = {5},

pages = {502–508},

abstract = {PURPOSE: This retrospective cohort study examined factors affecting the periodontal condition and survival of remaining teeth 5 years after removable partial denture (RPD) placement using multivariate analyses.nnMATERIALS AND METHODS: Of 231 patients who received RPDs at Tohoku University Hospital, 108 patients who had agreed to undergo a 5-year follow-up were examined. The outcomes of RPD treatment were assigned to one of three categories: successful (n = 58), remake (n = 36), and failure (n = 14). A total of 80 patients in the successful and remake groups were included in this study. The parameters analyzed to evaluate the periodontal condition were probing depth, Miller index of tooth mobility, and bone resorption level. Criterion variables were the outcome of each periodontal condition, deterioration, and tooth loss. Independent variables were sex, age, smoking habit, number of periodic maintenance appointments, location of RPD, number of abutment teeth, denture base material, design, and existence of a denture in the opposite jaw. Bivariate analyses were performed using chi-square test, and multivariate regression analysis was used to assess significance.nnRESULTS: Sex and frequency of maintenance care were independently associated with deterioration of the periodontal condition. Sex and existence of a denture in the opposite jaw were independently associated with tooth loss.nnCONCLUSION: The findings suggest that periodic maintenance care and condition of the opposite jaw are essential for maintaining the condition of the remaining teeth.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid27783470,

title = {A novel method of surface modification by electrochemical deoxidation: Effect on surface characteristics and initial bioactivity of zirconia},

author = {Juan Liu and Guang Hong and Yu-Han Wu and Kosei Endo and Jian-Min Han and Hiroyuki Kumamoto and Takeshi Wada and Hidemi Kato and Ping Gao and Keiichi Sasaki},

doi = {10.1002/jbm.b.33805},

issn = {1552-4981},

year  = {2017},

date = {2017-11-01},

journal = {J Biomed Mater Res B Appl Biomater},

volume = {105},

number = {8},

pages = {2641--2652},

abstract = {The aim of this study was to investigate and compare the surface characteristics and initial bioactivity of ceria-stabilized zirconia/alumina nanocomposite (NANOZR) with those of yttria-stabilized zirconia (3Y-TZP) and pure titanium (CpTi) following the use of three surface modification methods; polishing, sandblasting/acid-etching (SB-E) and electrochemical deoxidation (ECD). Physical properties including surface morphology, chemical composition, X-ray diffraction, surface wettability, surface roughness, and hardness were measured. Osteoblast-like MC3T3-E1 cells were used to examine cell morphology and attachment to the surfaces of the materials. ECD treated NANOZR (NANOZR-E) showed a well-arranged, self-organized microporous surface structure with significantly low contact angles when compared with the other specimens (p < 0.05). NANOZR-E also demonstrated a slight decrease in monoclinic phase content (-4.4 wt %). The morphology and attachment of MC3T3-E1 cells on NANOZR-E were similar to those on polished and SBE-treated CpTi surfaces. Higher cell affinity was observed on NANOZR-E when compared with ECD treated 3Y-TZP. The findings of this study indicate the effectiveness of the novel technique, ECD, in the formation of a microporous surface on NANOZR when compared with both CpTi and 3Y-TZP. Moreover, this method also appears to improve the biological activity of NANOZR during the initial stage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2641-2652, 2017.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid27801931,

title = {Association Between Tooth Loss, Receipt of Dental Care, and Functional Disability in an Elderly Japanese Population: The Tsurugaya Project},

author = {Takamasa Komiyama and Takashi Ohi and Yoshitada Miyoshi and Takahisa Murakami and Akito Tsuboi and Yasutake Tomata and Ichiro Tsuji and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1111/jgs.14390},

issn = {1532-5415},

year  = {2016},

date = {2016-12-01},

journal = {J Am Geriatr Soc},

volume = {64},

number = {12},

pages = {2495--2502},

abstract = {OBJECTIVES: To examine whether number of remaining teeth and regular dental care affect incident functional disability in elderly Japanese adults.nnDESIGN: Prospective cohort study.nnSETTING: Tsurugaya district, Sendai, Japan.nnPARTICIPANTS: Community-dwelling individuals aged 70 and older (N = 834).nnMEASUREMENTS: The outcome measurement was incident functional disability, defined as first certification of long-term care insurance in Japan, which is determined on the basis of a strictly established uniform nationwide standard. During a median follow-up of 7.9 years (interquartile range 4.8-7.9 years), information on long-term care insurance was obtained from the Sendai Municipal Authority. Oral health was assessed according to number of remaining teeth and presence or absence of regular dental care. Data were also collected on age, sex, body mass index, medical history, smoking, alcohol consumption, duration of education, depressive symptoms, cognitive impairment, physical functioning, and social support.nnRESULTS: Participants with 10 to 19 teeth (adjusted hazard ratio (aHR) = 1.42, 95% confidence interval (CI) = 1.03-1.94), one to nine teeth (aHR = 1.46, 95% CI = 1.04-2.03), and no teeth (aHR = 1.49, 95% CI = 1.03-2.14) were more likely to develop functional disability than those with 20 or more teeth. There was no significant difference in risk of functional disability between participants with 20 or more teeth and those with zero to 19 teeth who were receiving regular dental care, whereas those with zero to 19 teeth without regular dental care had a significantly greater risk of functional disability than those with 20 or more teeth (HR = 1.46, 95% CI = 1.11-1.92).nnCONCLUSION: Tooth loss was associated with greater risk of functional disability in community-dwelling elderly Japanese. Regular dental care might moderate the risk of functional disability in elderly individuals with missing teeth.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid26970439,

title = {Contribution of each masticatory muscle to the bite force determined by MRI using a novel metal-free bite force gauge and an index of total muscle activity},

author = {Minoru Takahashi and Satoshi Yamaguchi and Tsuyoshi Fujii and Makoto Watanabe and Yoshinori Hattori},

doi = {10.1002/jmri.25223},

issn = {1522-2586},

year  = {2016},

date = {2016-10-01},

journal = {J Magn Reson Imaging},

volume = {44},

number = {4},

pages = {804--813},

abstract = {PURPOSE: To develop a metal-free bite force gauge that can monitor the bite force in a strong magnetic field and to analyze the correlations between bite-force and total T2 shift of the mastication muscles.nnMATERIALS AND METHODS: The gauge used a micro-pressure sensor made of optical fiber. Ten subjects performed a 60-s isometric bite task at 40% of maximum clenching in various occlusal support conditions (intact dentition, right molar loss, or left molar loss). Spin-echo images were taken with a 1.5 Tesla scanner before and immediately after the task to correlate the bite force with the mean voxel count, mean shift in transverse relaxation time (ΔT2), and total T2 shift of each masticatory muscle.nnRESULTS: Measurements of total T2 shift identified significant correlations between the bite force and activities of the superficial layer of the bilateral masseter muscle, regardless of the occlusion condition (intact dentition: left, P = 0.007 and right, P < 0.001; right molar loss: left, P = 0.02 and right, P = 0.021; and left molar loss: left, P = 0.022 and right, P = 0.049). In contrast, significant correlations were not detected between the bite force and mean ΔT2 (intact dentition: left, P = 0.102 and right, P = 0.053; right molar loss: left, P = 0.393 and right, P = 0.868; and left molar loss: left, P = 0.531 and right, P = 0.92).nnCONCLUSION: Measurement of total T2 shift using a metal-free bite force gauge is a more sensitive index of individual muscle activity than mean ΔT2 during a bite task. J. MAGN. RESON. IMAGING 2016;44:804-813.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid27113040,

title = {Evaluation of masticatory activity during unilateral single tooth clenching using muscle functional magnetic resonance imaging},

author = {C Okada and S Yamaguchi and Y Watanabe and M Watanabe and Y Hattori},

doi = {10.1111/joor.12404},

issn = {1365-2842},

year  = {2016},

date = {2016-08-01},

journal = {J Oral Rehabil},

volume = {43},

number = {8},

pages = {583--590},

abstract = {Masticatory muscle activity during teeth clenching is affected by occlusal pattern. However, few studies have performed simultaneous evaluation of all masticatory activities during teeth clenching under various occlusal conditions. The aim of this study was to use muscle functional magnetic resonance imaging (mfMRI) to evaluate the effects of changes in occlusal point on masticatory activity during single tooth clenching. Changes in mean proton transverse relaxation time (∆T2) as an index of activity in all masticatory muscles during left unilateral clenching at the first molar or first premolar for 1 min were examined in nine healthy volunteers. Bite force was maintained at 40% of the maximum voluntary clenching force. The ∆T2 values of the masseter and lateral pterygoid muscles were analysed separately for superficial and deep layers, and for superior and inferior heads. The ∆T2 values for the ipsilateral deep masseter were significantly lower, and for the superior head of the ipsilateral lateral pterygoid muscles were significantly higher, after left first premolar clenching compared to left first molar clenching. These results quantitatively demonstrate a significant increase in activity of the superior head of the ipsilateral lateral pterygoid muscle and a significant decrease in activity of the ipsilateral deep masseter muscle with forward displacement of the occlusal contact point during unilateral tooth clenching.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid26657659,

title = {Enhancement of osteoblastic differentiation in alginate gel beads with bioactive octacalcium phosphate particles},

author = {Kosei Endo and Takahisa Anada and Masumi Yamada and Minoru Seki and Keiichi Sasaki and Osamu Suzuki},

doi = {10.1088/1748-6041/10/6/065019},

issn = {1748-605X},

year  = {2015},

date = {2015-12-01},

journal = {Biomed Mater},

volume = {10},

number = {6},

pages = {065019},

abstract = {The present study investigated whether alginate (Alg) hydrogel microbeads have a role in maintaining mouse bone marrow stromal ST-2 cells and release the cells after being stimulated by synthetic octacalcium phosphate (OCP), which is a mineral crystal capable of stimulating osteoblastic differentiation during a conversion process to hydroxyapatite (HA). The ST-2 cell suspension in the alginate solution, which contained various concentrations of OCP granules with diameters less than 53 μm, was extruded drop-wise into a stirred gelation solution containing BaCl2 using an encapsulator with nitrogen gas stream. The Alg-microbeads (Alg/OCP · ST-2 microbeads) that were generated, which had a diameter of approximately 400 μm, were incubated for up to 14 d and then assessed for osteoblastic differentiation. Alg-microbeads with cells were also incubated to identify the possible conversion from OCP to HA. Osteoblast differentiation markers in ST-2 cells, alkaline phosphatase (ALP) and collagen type I, were up-regulated in the presence of higher amounts of OCP. X-ray diffraction analysis and Fourier transform infrared spectroscopy confirmed that the OCP tended to convert to HA over time, suggesting that the OCP in Alg-microbeads interacts three-dimensionally with ST-2 cells and stimulates its osteoblastic differentiation. The release of ST-2 cells from the microbeads was also estimated. ST-2 cells were identified outside of the microbeads, although the cell number tended to decrease with increasing OCP. These results suggest that Alg/OCP microbeads could be used as a vehicle to activate osteoblastic cells and deliver them to sites where bone regeneration is needed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid25671229,

title = {Calcification during bone healing in a standardised rat calvarial defect assessed by micro-CT and SEM-EDX},

author = {H Okata and M Nakamura and A Henmi and S Yamaguchi and Y Mikami and H Shimauchi and Y Sasano},

doi = {10.1111/odi.12212},

issn = {1601-0825},

year  = {2015},

date = {2015-01-01},

urldate = {2015-01-01},

journal = {Oral Dis},

volume = {21},

number = {1},

pages = {74--82},

abstract = {OBJECTIVE: The study was designed to investigate the process of calcification during bone healing in a standardized rat calvarial bone defect model, measured by bone mineral density and the concentrations and distributions of calcium, phosphorus and carbon in the bone matrix.nnMATERIALS AND METHODS: A standard defect was made on the parietal bone of 12-week-old rats under anaesthesia. The rats were fixed in weeks 1, 2, 4 and 8,and the calvaria were resected and examined with microcomputed tomography, then frozen and sectioned for histology and analysed with energy-dispersive X-ray spectroscopy (EDX). Parietal bone of 12-week-old control rats was processed similarly.nnRESULTS: The mineral density of healing bone increased with time. The healing bone became thicker and denser with time in histology. The distributions of Ca and P expanded over the bone matrix, whereas that of C became localised and complemented that of C and P. The Ca/P concentration ratio increased, whereas the C/Ca and C/P ratios decreased in the healing bone matrix.nnCONCLUSION: Healing bone is immaturely calcified initially and proceeds calcification gradually, that is, as the bone volume increases, mineral increases in density and matures in quality, while organic components decrease.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid26599867,

title = {Involvement of IL-1 in the Maintenance of Masseter Muscle Activity and Glucose Homeostasis},

author = {Ko Chiba and Masahiro Tsuchiya and Masashi Koide and Yoshihiro Hagiwara and Keiichi Sasaki and Yoshinori Hattori and Makoto Watanabe and Shunji Sugawara and Makoto Kanzaki and Yasuo Endo},

doi = {10.1371/journal.pone.0143635},

issn = {1932-6203},

year  = {2015},

date = {2015-01-01},

journal = {PLoS One},

volume = {10},

number = {11},

pages = {e0143635},

abstract = {Physical exercise reportedly stimulates IL-1 production within working skeletal muscles, but its physiological significance remains unknown due to the existence of two distinct IL-1 isoforms, IL-1α and IL-1β. The regulatory complexities of these two isoforms, in terms of which cells in muscles produce them and their distinct/redundant biological actions, have yet to be elucidated. Taking advantage of our masticatory behavior (Restrained/Gnawing) model, we herein show that IL-1α/1β-double-knockout (IL-1-KO) mice exhibit compromised masseter muscle (MM) activity which is at least partially attributable to abnormalities of glucose handling (rapid glycogen depletion along with impaired glucose uptake) and dysfunction of IL-6 upregulation in working MMs. In wild-type mice, masticatory behavior clearly increased IL-1β mRNA expression but no incremental protein abundance was detectable in whole MM homogenates, whereas immunohistochemical staining analysis revealed that both IL-1α- and IL-1β-immunopositive cells were recruited around blood vessels in the perimysium of MMs after masticatory behavior. In addition to the aforementioned phenotype of IL-1-KO mice, we found the IL-6 mRNA and protein levels in MMs after masticatory behavior to be significantly lower in IL-1-KO than in WT. Thus, our findings confirm that the locally-increased IL-1 elicited by masticatory behavior, although present small in amounts, contributes to supporting MM activity by maintaining normal glucose homeostasis in these muscles. Our data also underscore the importance of IL-1-mediated local interplay between autocrine myokines including IL-6 and paracrine cytokines in active skeletal muscles. This interplay is directly involved in MM performance and fatigability, perhaps mediated through maintaining muscular glucose homeostasis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}