Survival time analysis of remaining teeth following replacement of unilateral free-end missing teeth: A comparison between fixed implant-supported prostheses and removable partial dentures.

OBJECTIVES: This retrospective study aimed to investigate the differences in tooth loss rate between fixed implant-supported prostheses (FISPs) and removable partial dentures (RPDs) in cases of unilateral free-end missing teeth. MATERIALS AND METHODS: The data of 324 patients who underwent treatment with FISPs or RPDs for unilateral free-end missing teeth and satisfied the applicable criteria, were evaluated (47 in the FISPs group and 277 in the RPDs group). After propensity score (PS) matching, which was used to extract patients with similar background factors related to prosthetic selection at baseline, survival time analyses were performed with tooth loss as the endpoint. The adjusted variables were age, sex, number of restored teeth, periodontal status, and the practicing dentist's experience in years. The remaining teeth were classified into subcategories in relation to the missing molars. RESULTS: Overall, 58 patients (29 in each group) selected by PS matching were evaluated in the final analysis. The total number of lost teeth was 35 (FISPs group: n = 10; RPDs group: n = 25). The mean (±SD) period to tooth loss and the 10-year survival rates in the FISPs and RPDs groups were 51.6 (±30.1) months and 42.3 (±29.7) months, 70.5% and 16.4%, respectively. The log-rank test showed that significantly longer survival time in FISPs compared with RPDs. CONCLUSIONS: After adjustments for confounding factors using PS matching, replacing unilateral free-end missing teeth with FISPs may exhibit a lower tooth loss rate in adjacent and contralateral teeth compared to replacing with RPDs.

Relationship between maximal isometric tongue pressure and limit of fracture force of gels in tongue squeezing.

BACKGROUND: There is no clear objective indicator for selecting soft foods that are required for food bolus formation in older people with impaired oral function. OBJECTIVE: This study aimed to investigate the relationship between maximal isometric tongue pressure (MITP) and the mechanical properties of gels that can be crushed by the tongue. METHODS: This study included 65 healthy participants aged 22-96 (young group; 15 males, 15 females; older dentate group; 7 males, 8 females; older edentulous group; 10 males, 10 females). MITP was measured by the balloon-probe device. Agar gel with 10 different kinds of fracture force from 10N to 100N was used. The limit of fracture force of gels (LFFG) that were crushed by the tongue was measured by the up-and-down method. In the older edentulous group, two items were measured with and without dentures. Spearman's rank correlation coefficient was used to evaluate the relationship between MITP and LFFG in each group (p < .05). RESULTS: There were positive correlations between MITP and LFFG in all groups (overall groups: rs = .66, young group: rs = .46, older dentate group: rs = .61, older edentulous group with dentures: rs = .60, older edentulous group without dentures: rs = .47). CONCLUSION: MITP and LFFG were positively correlated in young, older dentate and older edentulous groups, suggesting that MITP has the potential to be an objective indicator of the range of mechanical properties of soft food that can be crushed by the tongue.

Associations of sex, age, and number of remaining teeth with performance on oral hypofunction tests.

INTRODUCTION: Oral hypofunction comprises seven aspects of oral condition, including oral hygiene, oral dryness, bite strength, tongue-lip motor function, tongue pressure, masticatory function, and swallowing function. Each of these seven has a single diagnostic criterion; however, the use of a single indicator without consideration of sex, age, or other factors is controversial. The purpose of this study was to evaluate the association between the oral hypofunction test and sex, age, and number of remaining teeth. METHODS: The study was conducted at 12 facilities by the members of the Japanese Society of Geriatric Dentistry during April to December 2019. The participants comprised 181 healthy older adults aged 65 years and over (56.9% female; age range 65-95 years) who regularly visited these facilities. All tests of oral function and oral status available in Japan were performed on the participants, and the association between these tests and sex, age, and number of remaining teeth was examined. RESULTS: Sex differences were observed in masticatory function, bite force, lip closure force, jaw-opening force, oral diadochokinesis "ka," and tongue coating index (p < .05). In men, age was weakly (r = 0.20-0.40) associated with masticatory function, jaw-opening force, maximum tongue pressure, oral diadochokinesis, and swallowing function. In women, the number of remaining teeth, masticatory function, jaw-opening force, and oral diadochokinesis "ta" and "ka" was also weakly associated with age. CONCLUSIONS: Performance on the oral hypofunction test differs by sex, age, and number of remaining teeth. This means that the current single criterion for evaluation requires caution in its interpretation.

Association of oral frailty with medical expenditure in older Japanese adults: The study of late-stage older adults in Tottori (START Tottori).

OBJECTS: This study aimed to determine the association between annual medical expenses and oral frailty in later-stage older adults (aged ≥ 75 years). No studies have investigated the association between medical costs and oral frailty, which would elucidate the association between oral frailty and the deterioration of mental and overall physical function. MATERIALS AND METHODS: In this cross-sectional study, 2190 adults (860 men and 1330 women aged 75-94 years) covered by the Medical System for the Elderly and residing in Tottori Prefecture, Japan, between April 2016 and March 2019, were included. Participants were classified into three groups: healthy, pre-orally frail or orally frail, based on dental health screening findings. The medical and dental expenses over the years, number of days of consultations and comorbidities were obtained from the Japanese Health Insurance Claims Database. RESULTS: The number of days of medical and dental consultations and annual medical expenses for outpatient care differed among the three study groups. A significant association was observed between oral frailty and high annual expenses for outpatient medical and dental care. Oral frailty was associated with higher medical expenses in participants with poor masticatory function. Higher and lower dental expenses were associated with subjective poor masticatory function and subjective impairment of swallowing function respectively. CONCLUSION: Medical and dental expenses for orally frail older adults are high, indicating that oral frailty may be related to the occurrence and severity of diseases other than oral health issues. Future studies should examine the mechanism by which oral weakness affects physical and mental functions.

Relationship between carotid intima-media thickness and periodontal disease in a Japanese urban population with and without hypertension: The Suita Study.

AIM: To investigate the association between periodontal disease and atherosclerosis and to examine whether the association is modified by hypertension status. MATERIALS AND METHODS: In this cross-sectional study, 1472 Japanese individuals aged 50-79 years who underwent a medical check-up, dental examination, and carotid ultrasonography were studied. Carotid atherosclerosis was expressed as the maximum and mean carotid intima-media thickness (max-IMT, mean-IMT) and the presence of stenosis (≥75%). Periodontal status was examined by the Community Periodontal Index (CPI, codes 0-4). The participants were divided into three groups according to the periodontal status (CPI0-2, CPI3, CPI4). RESULTS: A positive correlation was found between mean-IMT and periodontal disease after adjustment for cardiovascular risk factors in the entire cohort (mean-IMT in hypertensives: CPI0-2: 0.848 mm, CPI3: 0.857 mm, CPI4: 0.877 mm; normotensives: 0.782, 0.802, 0.826). In the entire cohort, the multivariable-adjusted odds ratio of stenosis based on mean-IMT significantly increased according to periodontal status in normotensives (odds ratio; CPI0-2: 1, CPI3: 1.39, CPI4: 2.53; p-value for trend = .004) but showed only marginal significant increase in hypertensives (1, 1.15, 1.55; p-value for trend = .063). No significant relationships were observed for max-IMT in all analyses. CONCLUSION: We observed an association between periodontal disease and atherosclerosis in normotensive and hypertensive participants.

Association between prior-night sleep and next-day fatigue in older adults: a daily diary study.

BACKGROUND: Fatigue is known as an element of frailty. Sleep problems (e.g., short sleep duration and low sleep quality) can increase fatigue, but the day-to-day relationship between sleep and fatigue has not been studied well in older adults. Using a daily diary method, this study examined the within- and between-person associations between sleep and fatigue in older adults. METHODS: The study recruited 56 Japanese community dwellers (age: 82-86 years; female: 37.5%). Participants responded to a daily diary questionnaire at the end of each day. Over seven days, time in bed and satisfaction were measured after waking up, whereas fatigue was assessed before going to bed. We included person-level covariates (demographic factors, and physical and mental health) and day-level covariates (time in study, and positive and negative emotions). Multilevel models were estimated to examine within- and between-person associations. RESULTS: At the within-person level, on days following short and long time in bed and days following low levels of sleep satisfaction, individuals felt higher levels of fatigue compared with usual days. At the between-person level, no statistically significant differences in fatigue were observed between individuals with long and short time in bed. CONCLUSIONS: The findings suggest that prior-day sleep is associated with next-day fatigue in older adults. Long and short sleep duration and low sleep quality can lead to fatigue. Considering that sleep is a modifiable health behavior, appropriate management of sleep behavior may reduce fatigue.

Factors associated with weight loss by age among community-dwelling older people.

BACKGROUND: Factors associated with weight loss in community-dwelling older people have been reported in several studies, but few studies have examined factors associated with weight loss by age groups. The purpose of this study was to clarify factors associated with weight loss by age in community-dwelling older people through a longitudinal study. METHODS: Participants in the SONIC study (Longitudinal Epidemiological Study of the Elderly) were community-dwelling people aged 70 or older. The participants were divided into two groups: 5% weight loss and maintenance groups, and compared. In addition, we examined factors affecting weight loss by age. The analysis method used was the χ2 test, and the t-test was used for comparison of the two groups. Factors associated with 5% weight loss at 3 years were examined using logistic regression analysis with sex, age, married couple, cognitive function, grip strength, and the serum albumin level as explanatory variables. RESULTS: Of the 1157 subjects, the proportions showing 5% weight loss after 3 years among all subjects, those aged 70 years, 80 years, and 90 years, were 20.5, 13.8, 26.8, and 30.5%, respectively. In logistic regression analysis, factors associated with 5% weight loss at 3 years by age were influenced by BMI of 25 or higher (OR = 1.90, 95%CI = 1.08-3.34, p = 0.026), a married couple (OR = 0.49, 95% = 0.28-0.86, p = 0.013), serum albumin level below 3.8 g/dL (OR = 10.75, 95% = 1.90-60.73, p = 0.007) at age 70, and the grip strength at age 90 (OR = 1.24, 95%CI = 1.02-1.51, p = 0.034), respectively. CONCLUSIONS: The results suggest that factors associated with weight loss by age in community-dwelling older people through a longitudinal study differ by age. In the future, this study will be useful to propose effective interventions to prevent factors associated with weight loss by age in community-dwelling older people.

Force exerted on maxillary anterior teeth in mandibular unilateral and bilateral distal extension partial edentulous situation.

The purpose of this study was to determine the influence of mandibular unilateral and bilateral distal extension partial edentulous situation and the use of removable partial dental prostheses on the force exerted on maxillary anterior teeth. A commercially available jaw model with exchangeable teeth was used. Seven experimental conditions of mandibular distal extension edentulous situation were prepared and a distal extension removable partial dental prosthesis to replace missing posterior teeth was fabricated. The occlusal force was measured by inserting an occlusal force measuring film between the maxillary and mandibular teeth of the model. An occlusal load was applied and the forces and ratios were compared using the Kruskal-Wallis test and the Mann-Whitney U test (p < 0.05). As a result, the force exerted on the maxillary anterior teeth increased significantly as the number of remaining teeth decreased in unilateral and bilateral edentulous situation. The force exerted on the maxillary anterior teeth decreased significantly with use of a removable partial dental prosthesis. It is concluded that when the number of remaining teeth decreases in mandibular unilateral and bilateral distal extension partial edentulous situation, the burden on the maxillary anterior teeth increases. Our findings suggest that for patients with mandibular distal extension partial edentulous situation, using a removable partial dental prosthesis is effective in preserving the remaining teeth by reducing excessive force.

[Relationship between glycemic control and mental health in community-dwelling older people with diabetes mellitus: The SONIC study].

AIM: The purpose of this study was to examine the relationship between glycemic control and mental health in community-dwelling older people with diabetes mellitus (DM) from insights that contribute to the management of diabetes in consideration of quality of life (QOL). METHODS: We used the data of the Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC) study, a prospective cohort study of community-dwelling older people. The present study included 2,051 older subjects of 70±1 years, 80±1 years and 90±1 years of age. We conducted medical interviews, blood sampling, and the subjects were asked to complete a questionnaire (WHO-5-J) at the venue. Three hundred sixty-eight people were diagnosed with DM. The subjects of this study were 192 people who were undergoing drug therapy for glycemic control. A multiple regression analysis was performed to clarify the relationship between glycemic control (divided as follows: HbA1c<7.0%, good control group; HbA1c≥7.0%, poor control group) and the WHO-5-J score, as the dependent variable, after adjusting for any confounding factors. RESULTS: In subjects of 70 years of age, a negative association was found between glycemic control and the WHO-5-J score, with the good control group showing a significantly lower score (ß: -0.468, p<0.01) in comparison to the poor control group. In detail, we observed a significant difference in the sub-items of WHO-5-J, question item 3, "I have felt active and vigorous" at 70 years of age (good control group, 2.56±1.37; poor control group, 3.21±1.18; p=0.021) and question item 5, "My daily life has been filled with things that interest me" (good control group, 2.44±1.21; poor control group, 3.11±1.11; p=0.009). As for the two questions, the WHO-5-J scores were lower in the good control group. These associations showed no statistical significance at 80 years of age or 90 years of age. CONCLUSION: The results obtained in this study indicated that strict glycemic control management of diabetes mellitus may lead to a lower mental QOL in younger elderly individuals (70 years of age). Therefore, it is important to pay attention to the mental burdens of the management of glycemic control in older people with DM.

Physical performance reference values for Japanese oldest old: a SONIC study.

BACKGROUND: The oldest old, defined as those aged 90 or over, is now the fastest-growing population sector. This study aimed to determine reference values for several physical performance measures (PPMs) among 90-year-olds using internationally standardized measurements and to clarify the characteristics of these indices by comparing their results for 90-year-olds with those for older people 70 and 80. METHODS: We used the Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians (SONIC) study data from 2010 to 2018. The study subjects were 70, 80, and 90-year-olds in the target area eligible to participate in the venue. Excluding those certified for long-term care, the final number of eligible persons is 70s cohort 1000 (2010), 80s cohort 973 (2011), and 90s cohort 690. 90s cohort only consisted of three survey waves: 2012, 2015, and 2018. We used hand grip strength and score on the Short Physical Performance Battery (SPPB) for our physical performance measurements. In addition, we statistically analyzed sex and age differences. RESULT: The simple mean ± standard deviation (SD) for the 90-year-old respondents were in men, 24.1 ± 5.4 kg in hand grip strength, 0.80 ± 0.22 m/s in usual gait speed, 17.2 ± 6.73 s in 5times chair stand, 5.89 ± 4.42 s in tandem balance, and 8.3 ± 2.2 in SPPB respectively and in women, 14.4 ± 4.0 kg in hand grip strength, 0.72 ± 0.20 m/s in usual gait speed, 17.8 ± 7.89 s in 5times chair stand, 4.72 ± 4.35 s in tandem balance, and 7.5 ± 2.4 in SPPB, respectively. For all PPMs, the age 90 cohort was statistically significantly different from the age 70 and 80 cohorts (all trends P <  0.001). Hand grip strength decreased with a similar gradient with age cohort increase of 10 years for both sexes. In contrast, SPPB lower limb score showed a larger drop between the age 80 and 90 cohorts than between the age 70 and 80 cohorts. We also constructed sex-specific appraisal standards according to quintiles. CONCLUSIONS: Our study yielded inclusive sex-specific reference values and appraisal standards for major physical performance measures not certified as requiring long-term care, community-dwelling, oldest old Japanese. The characteristics of age-related decline in physical performance differed between the upper and lower extremity assessments.

Association of personality traits with polypharmacy among community-dwelling older adults in Japan: a cross-sectional analysis of data from the SONIC study.

BACKGROUND: Polypharmacy is a serious concern among older adults and is frequently related to adverse outcomes, including health problems, reduced quality of life, and increased medical expenses. Although personality traits are associated with health behaviors and diseases, the effect of polypharmacy on personality traits is unclear. Therefore, we examined the association of personality traits with polypharmacy among community-dwelling older adults. METHODS: This cross-sectional study analysed data on 836 community-dwelling older adults aged 69-71 years who participated in the Japanese longitudinal cohort study of Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians. Polypharmacy was defined as the intake of ≥ 5 medications concurrently. Personality traits were assessed using the Japanese version of the NEO-Five-Factor Inventory (NEO-FFI). A five-factor model of personality traits, including "neuroticism," "extraversion," "openness," "agreeableness," and "conscientiousness," was measured by the NEO-FFI. RESULTS: The average number of medications was about 3 in both men and women. Among the participants, polypharmacy was observed in 23.9% of men and 28.0% of women. Multivariable logistic regression analysis showed that neuroticism (adjusted odds ratio [aOR] per 1 point increase = 1.078, 95% confidence interval [CI] = 1.015-1.144) in men and extraversion (aOR = 0.932, 95% CI = 0.884-0.983) in women were associated with polypharmacy. CONCLUSIONS: Higher neuroticism in men and lower extraversion in women were associated with polypharmacy. This study suggests that personality traits may be involved in the process leading to the development of polypharmacy. Information on individual personality traits may help medical professionals in decision-making regarding medication management for lifestyle-related diseases.

Alcohol drinking patterns have a positive association with cognitive function among older people: a cross-sectional study.

BACKGROUND: The relationship between moderate alcohol drinking or other alcohol drinking patterns such as frequency, beverage type, and situation of drinking and cognitive function is not sufficiently clear in older people. The purpose of this study was to investigate the association between alcohol drinking patterns and cognitive function in community-dwelling Japanese people aged 75 and over. METHODS: This study was a cross-sectional design based on a prospective cohort study called the SONIC study. Subjects were older people aged 75-77 or 85-87 who voluntarily participated in 2016-2017. Drinking information was collected for daily drinking frequency, daily drinking intake, beverage type, and non-daily drinking opportunity. Cognitive function was measured using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Other potential confounding factors evaluated were age, sex, medical factors, and psychosocial factors. An analysis of covariance was performed to evaluate the MoCA-J score relative to drinking frequency or alcohol intake. Multiple regression analysis was performed to investigate the association between beverage type or non-daily drinking opportunity and the MoCA-J score. RESULTS: The final number of participants analyzed was 1,226. The MoCA-J score for participants who reported drinking alcohol 1-6 days/week was significantly higher than that for those who reported drinking none or every day. No significant difference in the MoCA-J score was observed relative to daily alcohol intake. In terms of beverage type, wine was associated positively with the MoCA-J score. Non-daily drinking opportunity was also associated positively with the MoCA-J score. CONCLUSIONS: Moderate-frequency drinking, wine consumption, and non-daily drinking opportunities were associated with higher cognitive function in community-dwelling Japanese aged 75 and over. Further longitudinal studies are needed to clarify the causal relationships.

Relationship between two pressure-sensitive films for testing reduced occlusal force in diagnostic criteria for oral hypofunction.

OBJECTIVE: To measure the occlusal force in the same group of patients with the Dental Prescale 50H type R and the Dental Prescale II, examine the association between them, and determine the reference value for Dental Prescale II that corresponds to the 50H type R 200 N reference value used to make a diagnosis of oral hypofunction. BACKGROUND: Reduced occlusal force, a measure of frailty in older persons, was previously determined with Prescale 50H type R pressure-sensitive film, but it has been replaced by the Prescale II. MATERIALS AND METHODS: The study participants were 441 men and women aged ≥ 65 (mean, 71.8 ± 5.3) years. The occlusal force was measured with the two different types of pressure-sensitive film, and their association was examined. Receiver operating characteristic curves for the Prescale II measured values were created with the 200 N reference value used for the 50H type R film as the cut-off value. RESULTS: The analysis set included 391 participants for whom measurements were obtained using both the 50H type R and the Prescale II. Linear regression analysis produced regression equations, and a ROC curve analysis provided reference values of 500 N for the Prescale II (without pressure filter) and 350 N for the Prescale II (with pressure filter). CONCLUSION: In occlusal force tests for making a diagnosis of oral hypofunction, reference values for the Prescale II (without pressure filter) and for the Prescale II (with pressure filter) were determined. The findings suggested that the Prescale II can be used as a diagnostic examination for oral hypofunction.

Deterioration of periodontal status affects declines in masticatory performance: The Suita study.

AIM: We aimed to clarify the association between deterioration of periodontal status and masticatory performance in a longitudinal follow-up study of a general urban population. MATERIALS AND METHODS: This study investigated 663 participants in the Suita study with no changes in the number of functional teeth or occlusal support areas during a 5-year follow-up period. Participants were classified into three groups according to changes in periodontal status during the survey period: a recovered group; a stable group; and a deteriorated group. Rate of masticatory performance change was calculated by subtracting the value at baseline from the value at follow-up and dividing the resulting value by the baseline value. RESULTS: Median rates of masticatory performance change were -11.7% in the recovered group, -19.2% in the stable group, and -30.8% in the deteriorated group, and these values were significantly different (p < .001). Multiple regression analysis revealed periodontal status group (recovered group: reference; stable group: p = .029; deteriorated group: p = .006) as an independent variable was significantly associated with the rate of masticatory performance change. CONCLUSION: The present results suggest that deterioration of periodontal status increases the risk of age-related declines in masticatory performance.

Will implants with a fixed dental prosthesis in the molar region enhance the longevity of teeth adjacent to distal free-end edentulous spaces?

OBJECTIVES: Clinical evidence demonstrating the effectiveness of implants in preventing tooth loss is limited because of the many risk factors involved in tooth loss. This retrospective cohort study investigated whether an implant in the molar region of a distal free-end edentulous space affects the loss of the most distal tooth after 6 years, adjusting for other risk factors associated with tooth loss using propensity score matching analysis. MATERIAL AND METHODS: A total of 571 subjects and 1,085 teeth adjacent to a distal free-end edentulous space were evaluated. At baseline, the 1,085 teeth were divided into two groups according to the presence or absence of a molar implant with a fixed dental prosthesis in the distal free-end edentulous space. Propensity score matching analysis was used to reduce the effects of bias by matching teeth with and without implants according to similar background factors at baseline. The adjusted variables were age group, occlusal support status, Kennedy classification, tooth position, tooth type, restoration status, dental caries, periodontal pocket depth, and condition of the opposing tooth. RESULTS: A total of 56 teeth (28 associated with a molar implant; 28 with no implant) were enrolled according to propensity score matching. Fisher's exact test showed that a molar implant significantly protected the tooth adjacent to the distal free-end edentulous space (p = .01). CONCLUSIONS: Within the limitations of this retrospective cohort study, it was found that implants in free-end edentulous spaces may be beneficial in extending the longevity of adjacent teeth. Further research will be necessary to confirm this finding.

Association of periodontal disease with atherosclerosis in 70-year-old Japanese older adults.

Periodontal disease and arteriosclerotic disease are greatly affected by aging. In this study, the association of conventional risk factors and periodontal disease with atherosclerosis was longitudinally examined in Japanese older adults. Subjects in this study were 490 community-dwelling septuagenarians (69-71 years) randomly recruited from the Basic Resident Registry of urban or rural areas in Japan. At the baseline examination, all subjects underwent socioeconomic and medical interviews; medical examinations, including examinations for carotid atherosclerosis, hypertension, diabetes mellitus, and dyslipidemia; and conventional dental examinations, including a tooth count and measurement of probing pocket depth (PPD). After 3 years, 182 septuagenarians who had no atherosclerosis at the baseline examination were registered and received the same examination as at the baseline. In the re-examination conducted 3 years after the baseline survey, 131 (72.0%) of the 182 participants who had no atherosclerosis at the baseline examination were diagnosed with carotid atherosclerosis. Adjusting and analyzing the mutual relationships of the conventional risk factors for atherosclerosis by multiple logistic regression analysis for the 171 septuagenarians with a full set of data, the proportion of teeth with PPD ≥ 4 mm was independently related to the prevalence of atherosclerosis (odds ratio: 1.029, P < 0.022). This longitudinal study of Japanese older adults suggests that periodontal disease is associated with the onset/progression of atherosclerosis. Maintaining a healthy periodontal condition may be an important factor in preventing the development and progression of atherosclerosis.

Association between declines in objective masticatory performance and salivary stress markers: The Suita study.

Dentists often encounter patients suffering from psychological and social stress due to declines in masticatory performance, making this a critical issue to manage. We aimed to clarify the relationships between salivary stress markers as objective indices of chronic stress and objective masticatory performance in a general urban Japanese population. Data from 880 participants (mean age, 65.8 years) in the Suita study were used. Salivary interleukin (IL)-6 and cortisol concentrations were measured by enzyme-linked immunosorbent assay. Objective masticatory performance was determined by measuring the increase in surface area test gummy jelly after 30 times chewing. Participants were divided into two groups based on masticatory performance: a decreased group (lowest quartile) and a non-decreased group (second to fourth quartiles). Odds ratios (ORs) of higher salivary levels of stress markers (highest quartile) according to masticatory performance were estimated using logistic regression analysis adjusting for age, sex, periodontal status, salivary flow rate and smoking habit. Salivary IL-6 level was significantly higher in the decreased group than in the non-decreased group. Logistic regression analysis showed the adjusted OR for higher salivary IL-6 was significantly higher in the decreased group than in the non-decreased group (OR = 1.92; 95% confidence interval = 1.33-2.76; P < .001). No significant associations were found between salivary cortisol and decreased masticatory performance in any analyses. Declines in objective masticatory performance may correlate with higher salivary IL-6 level as an objective index of chronic stress.

[Decrease in activity and its related factors under COVID-19 crisis in community-dwelling older people].

AIM: To prevent the transmission of the novel coronavirus [COVID-19] and stop its spread, a state of emergency was declared from April to May 2020. People were encouraged to refrain from outings and reduce their contact with people. The purpose of this study was to examine the subjective changes in the amount of activity under COVID-19 crisis among the elderly and the factors related to this decrease in activity. METHODS: This study was part of the SONIC study, an ongoing prospective cohort study targeting community dwelling older people in their 70, 80, 90s, and over 100 years old in different regions (urban and suburban) of Japan. Subjective changes in the amount of activity during the state of emergency were assessed via a mail questionnaire. RESULTS: The percentage decrease in activity for the subjects in their 70s, 80s, and 90s were 68.1% (513/753), 65.3% (324/496), and 56.0% (164/293), respectively. By region, 69.4% in urban, while 57.7% in the suburbs. In the 70- and 80-year-old cohorts, the decrease in activity was more frequent among those in urban areas than in suburban areas. In the 90-year-old cohort, the differences between the regions were attenuated, while the economic status and walking speed were significantly associated with a decrease in activity. CONCLUSIONS: The decrease in activity varied by age group and region, suggesting that approaches to preventing the adverse health effects associated with inactivity due to the COVID-19 crisis are more important in urban areas than in suburban ones.

The importance of stroke as a risk factor of cognitive decline in community dwelling older and oldest peoples: the SONIC study.

BACKGROUND: Cognitive impairment is a major health concern among older and oldest people. Moreover, stroke is a relevant contributor for cognitive decline and development of dementia. The study of cognitive decline focused on stroke as the important risk factor by recruiting older and oldest is still lagging behind. Therefore, the aim of this study was to investigate the importance of stroke as a risk factor of cognitive decline during 3 years in community dwelling older and oldest people. METHODS: This study was longitudinal study with a 3-year follow-up in Japan. The participants were 1333 community dwelling older and oldest people (70 years old = 675, 80 years old = 589, and 90 years old = 69). Data collected included basic data (age, sex, and history of stroke), vascular risk factors (hypertension, diabetes mellitus, dyslipidemia, atrial fibrillation, and current smoking), and social factors (educational level, frequency of going outdoors, long-term care (LTC) service used, and residential area). The Japanese version of the Montreal Cognitive Assessment (MoCA-J) was decline of ≥2 points was defined as cognitive decline. Multiple logistic regression analysis was used to investigate the association between stroke and other risk factors with cognitive decline during a 3-year follow-up. RESULTS: The fit of the hypothesized model by multiple logistic regression showed that a history of stroke, advanced age, and greater MoCA-J score at the baseline were important risk factors, while the presence of dyslipidemia and a higher educational level were protective factors that were significantly correlated with cognitive decline during the 3-year follow-up. CONCLUSIONS: The cognitive decline after the 3-year follow-up was influenced by the history of stroke and advanced age, while greater MoCA-J score at the baseline was positively associated with subsequent 3 years cognitive decline. The protective factors were the presence of dyslipidemia and a higher educational level. Therefore, these factors are considered important and should be taken into consideration when searching for creative solutions to prevent cognitive decline after stroke in community dwelling older and oldest people.

Factors Influencing the Localization of Mandibular Third Molars in Twins.

PURPOSE: The aim of the present study was to evaluate the genetic and environmental factors influencing the localization of mandibular third molars by analyzing the panoramic radiographs of twins. We examined the mandibular third molars of Japanese monozygotic (MZ) and dizygotic (DZ) twins recruited by the Osaka University Center for Twin Research. MATERIALS AND METHODS: The present study included 49 pairs (98 participants) of MZ twins and 11 pairs (22 participants) of DZ twins. Using panoramic radiography, we evaluated the degree of eruption of mandibular third molars according to the height of the alveolus bone and the third molar space/crown width ratio. Using co-twin control analysis and a generalized linear mixed model, we evaluated the effects of various factors, including gender, age, body height, number of teeth, length of the lower dental arch, existence of a second molar, bruxism, and previous orthodontic therapy. RESULTS: Body height, third molar space/crown width ratio, and length of the mandibular dental arch were related to the degree of mandibular third molar eruption and were strongly influenced by genetic factors rather than common or unique environmental factors. CONCLUSIONS: The degree of third molar eruption was more similar among MZ twins than among DZ twins; therefore, genetic factors can be expected to have more significant influence than will environmental factors. These results can help identify the trend of third molar eruption from a young age, allowing us to advise the early extraction of mandibular third molars for patients with a short stature, narrow retromolar space, or short mandibular dental arch. In addition, if the genes that influence the degree of eruption were identified, we would be better equipped to predict an individual's risk of impaction, and indications for extraction might change.