The effect of periodontal status and occlusal support on masticatory performance: the Suita study

The relationships between mastication and cognitive function: A systematic review and meta-analysis

Masticatory function such as chewing is expected to modify human cognitive function, and/or the possibility of improving cognitive function is also predicted. This systematic review investigated whether masticatory function affects cognitive function for older/young adults. Full articles written in English from January 2000 to April 2022 were collected using PubMed and Cochrane Library. Target outcomes were cognitive function test scores, cognitive processing speed (reaction time), and masticatory function. For each research question, two independent reviewers conducted the search and screening, data extraction, quality assessment, and risk of bias assessment. The reviewers resolved any disagreements by discussion. From 226 articles retrieved, 20 were included in this review. Older adults with lower scores on the cognitive function test had lower masticatory performance, lower chewing ability, chewing difficulty, and decreased number of teeth. An increased risk of cognitive impairment was found in older adults with masticatory dysfunction. For young adults, gum chewing significantly reduced the processing speed of cognitive tasks compared to no gum chewing. Although most of the evidence included had a low level of evidence and a high risk of bias because of the research designs, the results still suggest that mastication may be a factor in improving cognitive function.

The impact of residual ridge morphology on the masticatory performance of complete denture wearers

Statement of the problem

Morphology of the residual ridge (RR) is expected to influence the masticatory performance (MP) of complete denture (CD) patients, but considerable details of this relationship are unknown.

Purpose

We aimed to investigate the association between the objective MP and RR morphology of CD wearers and other contributory factors affecting their MP.

Materials and methods

Sixty-five patients with well-fitting upper and lower CDs with no complaints of pain were enrolled. The objective MP was measured using test gummy jelly and a fully automated measuring device. The RR form was divided into U-type, V-type, I-intermediate, and F-Flat, then combinations of upper and lower RR forms (combined RR) were classified. The height was measured using CD's denture basal surface replicas, while occlusal contact of CDs was assessed using a tooth contact analysis system. The relationship between surveyed factors and MP was evaluated using Spearman's rank correlation, Kruskal-Wallis test, generalized linear regression, and analysis of covariance.

Results

Participants with F-F and V-F combined RR forms had the lowest MP, while those with U-U and U-I forms had the highest MP, regardless of RR height. Participants with low RR height had the lowest MP, and those with high RR height had the highest MP, regardless of RR form. The analysis of covariance revealed that mandibular RR height, combined RR forms, and total occlusal contact area significantly affected the MP.

Conclusions

Our findings confirmed that the mandibular RR height, RR form combinations, and occlusal contact influence the MP of CD wearers.ClinicalImplications:The MP of CD wearers varied, depending on the height and form of the RR, as well as the occlusal contact area of the CDs. The results of this manuscript show that the morphology of the denture bearing area and the occlusion of the CDs are essential factors in predicting the treatment outcome of CD wearers. This allows the clinician to fabricate a complete denture with the denture basal surfaces adjusted and occlusion provided according to the patient. CD patients can be educated on how to chew to improve MP based on their own RR morphology.

Polyunsaturated Fatty Acids and Their Immunomodulatory Actions in Periodontal Disease

Polyunsaturated fatty acids (PUFAs) are a diverse set of molecules with remarkable contributions to human physiology. They not only serve as sources of fuel but also cellular structural components as well as substrates that provide bioactive metabolites. A growing body of evidence demonstrates their role in inflammation. Inflammation in the presence of a polymicrobial biofilm contributes to the pathology of periodontitis. The role PUFAs in modulating immuno-inflammatory reactions in periodontitis is only beginning to be uncovered as research continues to unravel their far-reaching immunologic implications.

Association between masticatory performance and oral conditions in adults: A systematic review and meta-analysis

OBJECTIVES

To give an overview of the evidence on the associations between oral condition factors and masticatory performance of adults, and to evaluate the direction and level of the associations.

DATA/SOURCES

Medline (PubMed), Embase (Ovid) and CINAHL Plus (EBSCOhost) were searched up to May 2022 for cross-sectional studies on oral conditions and masticatory performance in adults. Methodological quality of the included studies was independently evaluated based on the Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Data on the associations between oral condition factors and masticatory performance were extracted. Meta-analysis was conducted on correlation coefficients.

STUDY SELECTION

Of the 8,035 records identified, 97 articles (88 studies) were included in the qualitative synthesis, and 18 studies were included in the meta-analyses. Among the oral condition factors that had associations with masticatory performance, the number of natural/remaining teeth or functional tooth pairs was reported by the largest number of studies, followed by perioral muscle status, dental prosthetic status, oral moisture status and periodontal status. Results of the meta-analyses showed that the positive association with the number of natural/remaining teeth was the strongest (pooled correlation coefficient: 0.51, 95%CI: 0.48 to 0.54), followed by the number of functional tooth pairs, maximum tongue force/pressure, while the association with the oral moisture status was the weakest.

CONCLUSIONS

Number of natural/remaining teeth and functional tooth pairs, perioral muscle status, oral moisture status, dental prosthetic status and periodontal status are the main oral condition factors influencing masticatory performance. Based on the limited evidence available, among these factors, the number of natural/remaining teeth has the strongest positive association, with a very low quality of evidence.

CLINICAL SIGNIFICANCE

This study provides valuable information on the oral condition factors associated with masticatory performance, which would be important for policymakers and clinical practitioners when deciding on the strategies for improving the masticatory performance of adults. This review highlights the need for standardization of measures and classifications of masticatory performance and oral conditions.

REGISTRATION

PROSPERO (registration number: CRD42021256824).

Periodontal status is associated with oral function in community-dwelling older adults, independent of dentition status

OBJECTIVE

To determine whether periodontal status is associated with oral function, including masticatory performance and occlusal force, among community-dwelling older adults.

BACKGROUND

Although a potential association between periodontal status and oral function has been reported, variations in the root surface area (RSA) of each tooth have not been considered.

METHODS

We used data from a population-based study involving community-dwelling older adults. The RSA with periodontal ligament (RSA-PL), which quantifies the RSA attached to the periodontal ligament and alveolar bone, was calculated based on full-mouth periodontal examination. Masticatory performance was assessed using spectrophotometric measurement of the color (a* value) of color-changing chewing gum. The bilateral maximal occlusal force (MOF) was measured using a pressure-sensitive sheet and dedicated software. The associations of the RSA-PL, a quantitative marker of periodontal tissue support, with the a* value and MOF were assessed using linear regression models.

RESULTS

The analyses included data from 250 adults [60.8% women; age, mean (standard deviation) 82.5 (5.0) years]. On average, the study participants had an RSA-PL of 26.3 cm² , a* value of 25.0, and an MOF value of 555.1 N. After adjustments for potential confounders, including dentition status, age, sex, dental visit regularity, smoking status, physical activity level, depressive symptoms, a history of stroke or diabetes mellitus, and body mass index, the RSA-PL was found to be associated with the a* value [coefficient (per 1 cm² increase): 0.16, 95% confidence interval (CI) 0.10-0.22)] and MOF (coefficient: 9.2, 95% CI 5.3-13.1).

CONCLUSION

This study demonstrated that greater amounts of remaining tooth-supporting structures, indicated by higher RSA-PL values, were associated with better masticatory performance and a higher occlusal force among community-dwelling older adults.

Predictability and Clinical Stability of Barrier Membranes in Treatment of Periodontal Intrabony Defects: A Systematic Review and Meta-Analysis

The adjunctive use of GTR membranes helps us to achieve predictable periodontal regeneration. The aim of this systematic review was to evaluate and compare the treatment efficacy of resorbable versus non-resorbable barrier membranes used in guided tissue regeneration in the treatment of intrabony defects in chronic periodontitis patients. The following databases were searched: Medline, the Cochrane Central Register of Controlled Trails (CENTRAL), SCOPUS, EMBASE. Randomized clinical trials (RCTs) published in English languages over the past 25 years were included. The primary outcomes assessed were: change of probing pocket depth (PD), change in clinical attachment level (CAL) and gingival recession coverage (GRC), and intrabony defect fill (IBDF). A total of eight RCTs were included for systematic review. The outcome of GR at a six-month interval revealed a significant difference in treatment effect with a mean difference of 0.42, 95% CI [0.02, 0.81]; Z = 2.09, (p = 0.04) favouring the resorbable membrane group. The intrabony defect depth fill at a 12-month interval revealed a significant difference in treatment effect with MD of 0.79, p = 0.00001; favoring the resorbable membrane group. The resorbable membrane showed a significant improvement in gingival recession coverage and intrabony defect fill, owing to its advantage of avoiding the second surgical intervention.

The Association of Dietary Intake, Oral Health, and Blood Pressure in Older Adults: A Cross-Sectional Observational Study

Hypertension is related to impaired mastication that causes malnutrition, declining the general health of older adults. This study assessed the role of dietary intake in the relationship between oral health and blood pressure. Eight hundred ninety-four adults aged ≥65 years who independently lived in rural regions of Japan participated in this study. Hypertension was classified according to the guidelines of the Japanese Society of Hypertension. The oral condition was evaluated by analyzing the remaining teeth, occlusal force, posterior occlusal support, masticatory performance, oral moisture, and oral bacterial level. Dietary intake was assessed using a brief self-administered dietary history questionnaire. Mann-Whitney U, chi-square, Kruskal-Wallis tests, and logistic regression analyses were used to elucidate the factors related to hypertension. Normotensive, hypertensive, and history of hypertension were observed in 30.9%, 23.8%, and 45.3% of the participants, respectively. The factors significantly associated with the hypertension were age, body mass index, posterior occlusal support condition, and sodium-to-potassium ratio related to salt intake and/or vegetable intake. Participants without posterior occlusion significantly had higher risk of hypertension (odds ratio = 1.72). This study suggested that there was an association between oral health and hypertension, while the loss of occlusal support may influence nutritional intake conditions.

Assessment of masticatory function in the differential diagnosis of stage IV periodontitis: A pilot diagnostic accuracy study

BACKGROUND

After diagnosis of periodontitis is made, detection of stage IV cases is critical for appropriate management that may call for interdisciplinary care. This study aims to identify and assess the accuracy of a simple screening approach for practice and surveillance of stage IV periodontitis.

METHODS

Masticatory function assessments by both validated self-reported masticatory dysfunction questionnaire and dual-color chewing gum mixing ability test (index test) were conducted in 214 consecutive patients, followed by a full-mouth periodontal examination. Periodontal diagnosis was based on the 2017 World Workshop classification of periodontal diseases (reference standard). Multivariate logistic regression and area under the receiver operating characteristic curve (AUROC) analyses were performed.

RESULTS

Overall, the individual patient-reported masticatory dysfunction questions showed low to moderate accuracy for predicting Stage IV periodontitis. The objective measures of masticatory function by calculating the variance of hue from the chewing gum test performed better with an AUROC of 0.840. A diagnostic approach based on age, self-report of altered food type intake, and chewing gum test result exhibited excellent performance for predicting Stage IV periodontitis (sensitivity: 89.7%; specificity:76.3%; AUROC:0.912).

CONCLUSIONS

Once the presence of periodontitis has been established, a simple diagnostic approach that does not require specialized workforce, complex or lengthy assessment allows identification of Stage IV periodontitis patients. This is important as these patients require specific case work up and interdisciplinary care pathways. Additional studies are required to validate the findings in multiple populations. This article is protected by copyright. All rights reserved.

Patients scheduled to undergo esophageal surgery should have the highest priority for perioperative oral management triage: a cross-sectional study

OBJECTIVES

An increasing number of patients visiting the dental office have a growing need for perioperative oral management (POM) to prevent postoperative complications. Therefore, it is necessary to determine which patients should receive preferential POM. This study investigated the dental status of patients scheduled to undergo surgery and addressed the priority for POM.

METHODS

This retrospective study included a total of 150 patients who were scheduled to undergo surgery at the Department of Respiratory Surgery (DRS), Department of Neurological Surgery (DNS), Department of Gynecological Surgery (DGS), Department of Breast and Endocrine Surgery (DBES), and Department of Esophageal Surgery (DES) managed by the Perioperative Management Center of Okayama University Hospital. We compared the general and dental status of patients among the five groups.

RESULTS

The DES group had significantly fewer teeth than the DBES group (p = 0.012), more severe periodontitis than both the DBES (p = 0.005) and DNS groups (p = 0.020), and poorer molar occlusal support status than both the DBES (p = 0.002) and DGS groups (p = 0.041). The DES group exhibited a significantly higher median age (p = 0.002), a higher ratio of males (p < 0.001), a higher prevalence of malignant tumors (p < 0.001), and higher proportions of smokers (p < 0.001) and drinkers (p < 0.001) than the other groups.

CONCLUSION

Patients who underwent surgery at the DES had more dental problems than other surgery patients. Accordingly, these patients should be given the highest priority for POM triage.

A cross-sectional study of relationships between periodontal disease and general health: The Hitachi Oral Healthcare Survey

BACKGROUND

This cross-sectional study performed to clarify the relationship between periodontal disease and non-communicable diseases (NCDs), such as obesity, diabetes mellitus, impaired glucose tolerance (IGT), chronic obstructive pulmonary disease (COPD), and atherosclerotic cardiovascular disease (ASCVD) by introducing dental examinations into the annual health examinations conducted by Japanese companies, and to highlights the importance of a medical system that connects dental and medical professionals.

METHODS

A total of 1.022 Hitachi Ltd. employees were enrolled in this cross-sectional study. We examined correlations and odds ratios (ORs) between the dental and overall health of employees using stratification and multiple logistic regression analyses based on the periodontal health indicators, general health indicators, and occlusal force.

RESULTS

The adjusted OR of PPD for obesity (OR, 1.42; 95% confidence interval [CI], 1.09-1.84; p = 0.009), IGT (OR, 1.48; 95% CI, 1.00-2.20; p = 0.049), and COPD (OR, 1.38; 95% CI, 1.02-1.88; p = 0.038) significantly differed. The adjusted OR of body mass index (OR, 1.28; 95% CI 1.15-1.42; p < 0.001), haemoglobin A1C (HbA1c) (OR, 4.34; 95% CI, 1.89-9.98; p < 0.001), fasting blood glucose (FBG) levels (OR, 1.08; 95% CI 1.04-1.11; p < 0.001), postbronchodilator forced expiratory volume in one second/forced vital capacity ratio (%FEV1) (OR, 0.95; 95% CI 0.91-1.00; p = 0.031) and smoking (OR, 2.32; 95% CI 1.62-3.33; p < 0.001) for severe periodontal disease also significantly differed. Occlusal force was significantly reduced in employees aged 50-59 years compared to those aged 40-49 years. Both PPD, HbA1c, FBG levels were significantly associated with occlusal force among employees with moderate/severe periodontitis. PPD was significantly associated with occlusal force among employees with and moderate COPD, and ASCVD. %FEV1 was significantly associated with occlusal force among employees with IGT.

CONCLUSIONS

This cross-sectional study revealed mutual relationships among periodontal disease, NCDs, and occlusal force on Japanese corporate workers. We demonstrated that a comprehensive, regional healthcare system centred on annual integrated dental and physical health examinations in the workplace will benefit employees and positively impact corporate health insurance.

Lower Masticatory Performance Is a Risk for the Development of the Metabolic Syndrome: The Suita Study

Objectives: Declined masticatory function has recently been receiving attention as a risk factor for poor general health. The present longitudinal analysis was conducted to clarify the relationship between decreased masticatory performance and the development of the metabolic syndrome (MetS) in a general urban cohort in Japan.

Methods: We surveyed 599 participants (254 men, 345 women; mean age at baseline, 65.8 ± 7.8 years) who underwent physical health checkups in the Suita study. We evaluated masticatory performance at baseline using test gummy jelly and divided participants into two groups: a “Lower group,” comprising participants in the lower 25% of the masticatory performance at baseline; and a “Normal group,” comprising all others. We estimated hazard ratios (HRs) for the Lower group by using Cox proportional hazard regression analysis to develop the MetS and the components of the MetS at follow-up, adjusting for age, smoking status, and periodontal status.

Results: On Cox proportional hazard regression analysis, the multivariable adjusted hazard ratio for the development of the MetS in the Lower group was 2.24 (95% confidence interval, 1.12–4.50) in men. The multivariable adjusted hazard ratio for the development of high blood pressure was 3.12 (1.42–6.87), for high triglycerides was 2.82 (1.18–6.76), and for high fasting plasma glucose was 2.65 (1.00–7.00) in men.

Conclusions: Lower masticatory performance suggested to be a risk factor for the development of the MetS as well as MetS components such as high blood pressure, high triglycerides, and high fasting plasma glucose in Japanese men.

A conceptual model of oro-facial health with an emphasis on function

The individual inclination to lead an autonomous life until death is associated with requirements that may be of physiological, psychosocial and environmental nature. We aim to describe a conceptual oro‐facial health model with an emphasis on oro‐facial function, taking the domains of quality of life and patient‐centred values into account. In the context of oro‐facial function, the requirements of life are met when the oro‐facial system is in a fit state. ‘Fitness of the oro‐facial system, that is oro‐facial health, is a state that is characterised by an absence of, or positive coping with physical disease, mental disease, pain and negative environmental and social factors. It will allow natural oro‐facial functions such as sensing, tasting, touching, biting, chewing, swallowing, speaking, yawning, kissing and facial expression’. In the presented conceptual model of oro‐facial health, it is postulated that each individual has present and future potentials related to biological prerequisites and resources that are developed by an individual through the course of life. These potentials form the oro‐facial functional capacity. When the individual potentials together do not meet the requirements of life anymore, dysfunction and disease result. The oro‐facial system is subject to physiological ageing processes, which will inevitably lead to a decrease in the oro‐facial functional capacity. Furthermore, comorbid medical conditions might hamper oro‐facial function and, alongside with the ageing process, may lead to a state of oral hypofunction. Currently, there is a lack of widespread, validated, easy‐to‐use instruments that help to distinguish between states of oro‐facial fitness as opposed to oral hypofunction. Clearly, research is needed to establish adequate, validated instruments alongside with functional rehabilitation procedures.

Trends in socioeconomic inequality of periodontal health status among Dutch adults: a repeated cross-sectional analysis over two decades

Background

Studies exclusively focusing on trends in socioeconomic inequality of oral health status in industrialized countries are relatively sparse. This study aimed to assess possible differences in oral hygiene and periodontal status among people of different socioeconomic status (SES) in the Netherlands over two decades.

Methods

A repeated cross-sectional analysis of 3083 participants aged 25–54 years was conducted on the Dutch National Oral Health Surveys of 1995, 2002, 2007, and 2013. Plaque-free was defined according to the Simplified Oral Hygiene Index (OHI-S = 0). Periodontal status was classified in two different ways, either periodontal health/disease (probing pocket depth index [PDI] = 0/ ≥ 1) or with/without deep pockets (PDI = 2). We used the regression-based absolute and relative effect index to measure the absolute and relative socioeconomic inequalities. Multivariable logistic regressions were used to explore temporal trends in oral hygiene and periodontal status by low- and high-SES groups.

Results

Age-standardized percentages of individuals with plaque-free increased in the whole population from 1995 to 2013 (12.7% [95% CI 10.5–14.9] to 28.1% [24.8–31.5]). Plaque-free showed significant socioeconomic differences in absolute and relative inequalities in 2007 and 2013. Between 1995 and 2013, age-standardized percentage of periodontal health increased (from 51.4% [48.1–54.7] to 60.6% [57.0–64.1]). The significant absolute inequalities for periodontal health were seen in 2002 and 2013. The relative scale presented a similar pattern. Regarding deep pockets, there was little difference in the age-standardized overall prevalence in 1995 versus 2013 (from 6.5% [4.9–8.2] to 5.4% [3.7–7.0]). The significant absolute and relative inequalities in deep pockets prevalence were found in 1995. Yet, all interaction terms between survey year and SES did not reach significance (plaque-free: P = .198; periodontal health: P = .490; deep pockets: P = .678).

Conclusions

Socioeconomic inequalities in oral hygiene and periodontal status were present in the Netherlands in the last two decades.

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.

Perceived general health in relation to oral health status in a rural Kenyan elderly population

Background

This study aimed to determine the present oral health status of the rural Kenyan elderly population and to investigate whether oral health status is associated with the perceived general health.

Methods

A total of 131 individuals aged 65 years and over in Mbita Constituency, Homa Bay County in Kenya were randomly selected and visited at home. The home visit study, which was conducted from 2014 to 2016, included oral examination by a dentist and administration of a self-reporting questionnaire. The number of teeth present and functional tooth unit (FTU) points were calculated using the dental chart. Perceived general health, subjective masticatory ability, and self-reported periodontal symptoms were collected using a questionnaire sheet. Fisher’s exact test and nonparametric test were used to determine the difference in percentage and means. The odds ratio of good general health based on the participants’ masticatory satisfaction was calculated by logistic analysis.

Results

Satisfactory mastication was dependent on the number of teeth present, FTU points, and self-reported “gum bleeding” and “tooth mobility”. Furthermore, satisfactory mastication was associated with perceived general health status independent of sex and age. The adjusted odds ratio of good perceived general health was 2.29 (95% confidence interval 1.05–4.99) for participants who had the subjective masticatory ability.

Conclusion

Among the Kenyan elderly population, satisfactory mastication was related to the number of teeth present, FTU points, and self-reported periodontal symptoms. Furthermore, satisfactory mastication was associated with perceived general health status independently.

Higher Masticatory Performance and Higher Number of Chewing Strokes Increase Retronasal Aroma

Mastication is a physiological process whereby food is comminuted and mixed with saliva to form a swallowable bolus; it is also the initial process for retronasal aroma that is released from foods to receptors in the nose. However, the influence of mastication state on retronasal aroma is poorly understood. The purpose of this study was to investigate the relationship between aroma concentration and factors related to mastication state. The study design was an analytical observational study. Twelve male volunteers (age, 26.5 ± 2.7 years) were recruited and divided into five and seven participants in the low and high masticatory performance groups, respectively. The stimulated salivary flow rate was measured while participants chewed paraffin wax. First, an odor sensor was placed in the nostril, and the aroma concentration was measured over time as participants chewed an orange-flavored gummy jelly standardized for masticatory performance assessment until swallowing; chewing strokes were counted to determine swallowing thresholds. Next, participants were instructed to chew the gummy jelly for a certain number of strokes (i.e., 50 or 100% of swallowing thresholds, as well as 30 strokes) and expectorate the jelly without swallowing. The surface area of comminuted jelly at 30 chewing strokes was defined as masticatory performance. Maximum and slope of aroma concentration, surface area, number of chewing strokes, and stimulated salivary flow rate were compared between low and high masticatory performance groups. Statistical significance was set at α = 0.05. At 30 chewing strokes, the maximum aroma concentration and the slope were significantly greater in the high masticatory performance group than in the low masticatory performance group. There was a positive correlation between the maximum aroma concentration and the number of chewing strokes with aroma release in both groups. No significant correlation was found between the maximum aroma concentration and the stimulated salivary flow rate. However, multiple regression analysis (with aroma concentration as a dependent variable) showed that the increase in surface area, the number of chewing strokes, and the stimulated salivary flow rate were significant explanatory variables. The results suggested that retronasal aroma was influenced by mastication state and salivary flow rate during chewing.

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.

Impact of adjunctive procedures on recombinant human fibroblast growth factor-2-mediated periodontal regeneration therapy: A retrospective study

BACKGROUND

Human fibroblast growth factor-2 (rhFGF-2) therapy has been used for periodontal tissue regeneration. However, few studies have reported their adjunctive procedures based on strategy of tissue engineering. The aim of this retrospective study is to assess the adjunctive effects of modified papilla preservation technique (mPPT) and combination with autogenous bone grafts (AG) on the rhFGF-2 therapy.

METHODS

Total of 44 sites underwent rhFGF-2 therapies and the evaluations in the survey periods. The primary outcome was set to the radiographic bone fill by radiographic examinations at 6 and 12 months after surgeries. We analyzed the correlation between influencing factors and the primary outcome, and differences of therapeutic effect by combination therapy with mPPT and that with AG.

RESULTS

After surgeries, probing depth (PD), clinical attachment level (CAL) and bone defects significantly improved. The improvements of radiographic bone fill were significantly positive correlated with a number of bone walls, combination with mPPT, and AG at 6 months after surgeries, and with combination with mPPT and AG at 12 months after surgeries. The significant differences of improvements of radiographic bone fill were demonstrated between combination with or without mPPT at 12 months after surgeries, and with or without AG at 6 and 12 months after surgeries. Moreover, the multiple linear regression analysis for the radiographic bone fill indicated the significant regression coefficient with conducts of mPPT.

CONCLUSIONS

mPPT and AG had powerfully adjunctive effects on rhFGF-2 therapy. Further studies are needed in order to verify by randomized clinical trials.

A prediction model of masticatory performance change in 50- to 70-year-old Japanese: The Suita study

OBJECTIVES

Declines in masticatory performance might be a risk factor for worsening nutritional intake and result in general frailty. The present study constructed and investigated a method to predict the extent to which objective masticatory performance declines with age in cases with poor oral health status.

METHODS

Participants comprised 1201 participants in the Suita study with dental checkup at both baseline and follow-up (500 men and 701 women; age at baseline, 65.6 ± 7.8 years; mean follow-up, 5.1 ± 1.1 years). First, multiple linear regression analysis was performed with masticatory performance at follow-up as the dependent variable and sex as well as baseline age, number of functional teeth, maximum bite force, occlusal support, periodontal status, salivary flow rate, and masticatory performance as independent variables. Scores were assigned to each factor based on the standardized partial regression coefficient obtained from multiple linear regression analysis. Participants were divided into quintile groups (Q1-Q5) based on total scores for factors, and rates of masticatory performance change for each group were calculated and compared.

RESULTS

Mean rates of masticatory performance change in groups Q1-Q5 from the model to predict declining masticatory performance were: Q1, -9.7%; Q2, -12.7%; Q3, -18.0%; Q4, -19.9%; and Q5, -29.8%.Thus there was a trend for masticatory performance to decrease with decreasing score.

CONCLUSIONS

The model developed in this study quantitatively predicted declines in masticatory performance after approximately 5 years.

CLINICAL SIGNIFICANCE

We developed a model for predicting the extent to which masticatory performance will change over the next 5 years. This model may offer a useful tool when taking measures to prevent declines in masticatory performance with aging.

Factors Influencing Changes in Masticatory Performance as a Result of Wearing Removable Partial Dentures in Patients with Partially Edentulous Arches

PURPOSE

To measure masticatory performance (MP) in partially edentulous patients when wearing removable partial dentures (RPDs) versus when not wearing RPDs, and to identify factors that could enable clinical evaluations related to differences in MP.

MATERIALS AND METHODS

This study consisted of 87 partially edentulous patients (57 females, 30 males; mean age, 69.41 ± 8.85 years) categorized as Eichner classification B who habitually wore RPDs. MP was evaluated while wearing versus while not wearing RPDs using test gummy jellies. The participants were categorized into four groups by the presence of occlusal contacts in one to three of the molar and premolar regions (occlusal support), or in the anterior region only, according to the Eichner index (B1-B4). The participants were also categorized according to the jaw on which the RPDs were worn and the Kennedy classification, and evaluated in regard to changes in MP resulting from wearing RPDs. Additionally, the rate of change in MP (MP-rv) was calculated for each participant using MP when not wearing RPDs as a reference, and factors affecting MP-rv were evaluated using single or multiple regression analysis and the Kruskal-Wallis test with multiple comparisons.

RESULTS

Significant increases in MP-rv were observed for all participants and for those with occlusal support in two (p = 0.006) and three regions (p = 0.019); however, no significant differences were observed when wearing and not wearing RPDs in participants with (p = 0.090) and those without occlusal support in one region (p = 0.474). With respect to the jaw on which the RPDs were worn, only maxillary or both maxillary/mandibular RPDs tended to have higher MP-rvs than did only mandibular jaws. The results of the multiple regression analysis showed that Kennedy Class I edentulous arches were a factor in increasing MP-rv (standard partial regression coefficient = 0.46, p < 0.05).

CONCLUSION

According to the results of this study, among various factors on the degree of improvement in masticatory performance by wearing RPDs, bilateral missing posterior teeth might be a predictor for achieving clinical improvement.

Association among kidney function, frailty, and oral function in patients with chronic kidney disease: a cross-sectional study

Background

Chronic kidney disease (CKD) involves many factors that can cause frailty and oral hypofunction. We aimed to investigate the prevalence of frailty and oral hypofunction and to examine the associations among kidney function, frailty, and oral function in adults with CKD in Japan.

Methods

This cross-sectional study was conducted at two institutions. The participants included 109 patients with CKD stages 3–5 who visited outpatient clinics or were admitted for inpatient treatment. Frailty was evaluated using the Japanese version of the Cardiovascular Health Study frailty criteria. Oral function was evaluated by assessing oral motor skills [oral diadochokinesis (ODK) rate], masticatory ability, and the repetitive saliva swallowing test. The estimated glomerular filtration rate (eGFR) was used to indicate kidney function. We examined the associations among kidney function, frailty, and oral function using binomial logistic regression analysis.

Results

In total, 31 participants (28.4%) were classified as being frail. Univariate analysis showed that age, body mass index, eGFR, and haemoglobin level were significantly associated with frailty. ODK and swallowing function were significantly associated with frailty. Multivariate analysis revealed that frailty was significantly associated with eGFR [odds ratio (OR) 0.96, 95% confidence interval (CI) 0.92–1.00, p = 0.048] and ODK rate (OR 0.68, CI 0.47–0.98, p = 0.038). However, no significant association was found between CKD severity and masticatory or swallowing function.

Conclusion

We found a high prevalence of frailty in patients with CKD and a significant association between frailty and oral motor skills, affecting the swallowing function of patients with nondialysis CKD. The high prevalence of frailty among patients with CKD suggests that routine assessment of frailty is necessary to prevent the development of severe complications. In addition, oral and kidney function should be carefully evaluated, and oral health education and interventions should be performed for patients with CKD.

Patient-based outcomes and quality of life

Patient-based outcomes complement clinical data with patients' self-evaluation of their physical, psychological, and social well-being, and as such facilitate clinical decision-making, assessing the quality of care provided, and evaluating practices and policies. Some validated generic oral health-related quality of life measures used in recent research indicated a high performance. There is a proportional relationship between the quality of life and periodontitis, ie, the higher the level of periodontitis, the poorer the oral health-related quality of life. This relationship is heightened by the presence of symptoms such as bleeding, halitosis, and mobility. On the other hand, periodontal treatment has demonstrated the capability to improve quality of life substantially. Future research should focus on questionnaires that are able to explain the interlinked pathways between periodontal conditions, approaches to treatment approaches, and patients' well-being. The acquisition of new knowledge in the field is essential for the whole community, as we treat people not millimeters.

Factors related to removable denture use in independent older people: A cross-sectional study

BACKGROUND

Denture use for recovery of major tooth loss can reduce the need for care, and thus, it is important for dentists to identify the types of patients who use removable dentures.

OBJECTIVE

To identify factors associated with removable denture use in independent older Japanese people.

METHODS

This cross-sectional study investigated the oral condition; demographics; lifestyle; dental visit behaviour; and higher-level functional capacity, as assessed using the Tokyo Metropolitan Institute of Gerontology index of competence (TMIG index), of independent older people aged 65-74 years. Participants were divided into four groups based on sex and condition of the posterior occluding pairs (POPs). Multivariate-adjusted logistic regression analyses were performed for each group, with denture use or non-use as the dependent variable and the other items as independent variables.

RESULTS

Denture use or non-use was significantly associated with only dental consultation behaviour (regular dental visits and time since the last dental visit) in all groups. Subsequent analyses excluding dental consultation behaviour demonstrated that denture use or non-use was significantly associated with educational background in female participants with decreased POPs, with the type of household in male participants with lost POPs and with the TMIG index (social role) in female participants with lost POPs.

CONCLUSIONS

Denture use was associated with dental consultation behaviour. We revealed factors related to denture use or non-use in females with decreased POPs and both males and females with lost POPs.

The impact of oral health on physical fitness: A systematic review

Background

Oral health problems may have numerous effects on general health, including physical fitness and performance. In this review, we aimed to systematically review the available evidence to assess the effect of oral health on general physical fitness.

Methods

We systematically performed a literature search in two different databases (PUBMED and EMBASE) without restriction to the year of publication. Articles were included if the subjects were humans and the primary aim was to assess the effects of dental and/or oral health problems on physical activity using either objective physical measurements or physical performance tests. The quality of the studies was then assessed using a Joanna Briggs Institute (JBI) Critical Appraisal tool.

Results

A total of 2651 articles were initially retrieved from the systematic search of the literature. Of these, a final total of 11 articles following the inclusion criteria were included in the review. All of the 11 articles included in the review had good methodological quality. Of the 11 articles, ten articles suggested a correlation between dental and oral condition toward physical fitness, body balance, cardiorespiratory function, and also cognitive function. Only one article found contradictory results, which showed that periodontal conditions did not correlate with the cardiorespiratory function. Malocclusion, including the number of remaining teeth, was reported in five studies (45.4%), periodontal disease was evaluated in six studies (54.5%), along with slight evaluation of periapical inflammation.

Conclusion

This review suggests that there is a negative effect of poor dental and/or oral health on physical fitness and performance.

Brain-derived neurotrophic factor is related to stress and chewing in saliva and salivary glands

Chewing is one of the most important orofacial functions. During this process, food is reduced in size, while saliva moistens the food and binds it into a bolus that can be easily swallowed. Characteristics of the oral system, including the number of teeth, bite force, and salivary flow, influence the masticatory process. In addition, salivary glands produce several cell growth factors and play an important role in human health. The nerve growth factor (NGF) family consists of NGF, brain-derived neurotrophic factor (BDNF), and neurotrophins-3 to 7. BDNF is a well-studied neurotrophin involved in the neurogenesis, differentiation, and maintenance of select peripheral and central neuronal cell populations during development and adulthood. However, there has been no detailed description of the expression of neurotrophins other than NGF in the salivary gland. We previously studied the effect of immobilization stress + chewing on BDNF secretion and its receptor, tyrosine receptor kinase B, in rat submandibular glands and found increased BDNF expression in duct cells under these conditions. In this review, we describe recent advances in understanding the role of stress and chewing-related BDNF in the saliva and salivary glands.

Periodontitis: A Multifaceted Disease of Tooth-Supporting Tissues

Periodontitis is an infection-driven inflammatory disease in which the composition of biofilms plays a significant role. Dental plaque accumulation at the gingival margin initiates an inflammatory response that, in turn, causes microbial alterations and may lead to drastic consequences in the periodontium of susceptible individuals. Chronic inflammation affects the gingiva and can proceed to periodontitis, which characteristically results in irreversible loss of attachment and alveolar bone. Periodontitis appears typically in adult-aged populations, but young individuals can also experience it and its harmful outcome. Advanced disease is the major cause of tooth loss in adults. In addition, periodontitis is associated with many chronic diseases and conditions affecting general health.

Masticatory Dysfunction by Extensive Tooth Loss as a Risk Factor for Cognitive Deficit: A Systematic Review and Meta-Analysis

Background: An amount of cognition decline is normal with aging; however, intrinsic and extrinsic risk factors may exacerbate it, affecting social and occupational tasks. Masticatory dysfunction (MD), as a general term, refers to an impairment in the masticatory function triggered by a structural factor, such as tooth loss; functional factors, such as weaker bite force or a poorer masticatory performance; or both factors. MD acting as a source of chronic stress, promotes functional and morphological changes on the hippocampus, a brain area crucial for learning and memory abilities. This study aimed to synthesize evidence on the association between MD and cognitive deficit (CD), and demonstrate whether might be adequately considered as a risk factor.

Methods: Observational studies were screened in seven online databases; the search strategy (PECO) was focused in observational studies with humans as a population (P), presenting groups exposed (E), and non-exposed (C) to tooth loss, in which cognition parameters were measured and compared between groups (O). The final selection included only those studies comparing the effect in cognition between subjects having ≥20 remaining teeth and <20 remaining teeth, considering the latter as a structural factor triggering MD by the literature. Searching and data extraction were conducted following PRISMA guidelines. Qualitative and risk of bias evaluations were performed. The meta-analysis (MA) was constructed including the odds ratio (OR) and its 95% confidence interval (CI) comparing two groups—with/without MD. The level of evidence was rated by Grading Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results: In total, 5,666 citations were identified, 14 accomplished our eligibility criteria, and nine were include in the MA. The MA demonstrates that individuals with MD had 46% higher chance to presented CD (OR 2.24 [1.73, 2.90], p < 0.00001, I² = 46%). The level of evidence was rated as low by GRADE.

Conclusion: Despite the low certainty in evidence, according to our MA, MD is positively associated with increased risk of CD. However, more studies including other factors underlying MD and similar measurements should be conducted to obtain a strong estimate of the risk.

Masticatory satisfaction, ability, and performance in partially dentate patients after periodontal therapy

Abstract Introduction Understanding the effects of periodontal therapy is essential in performance and satisfaction of partially dentate patients. Objective To assess the effect of subgingival periodontal treatment in performance and masticatory satisfaction and ability as reported by partially dentate patients with untreated chronic periodontitis. Materials and method Patients were given nonsurgical periodontal treatment and masticatory satisfaction, ability, and performance were evaluated before and after treatment. Performance was assessed based on sieving chewed standardized chewable material, while satisfaction and ability were analyzed using a questionnaire based on OHIP-EDENT. Result Mean numbers of functional tooth units were 10.36 ± 1.43 anterior and 6.73 ± 0.79 posterior teeth. Masticatory performance did not vary significantly (p = 0.075), and mean particle sizes before and after treatment were 4.23 ± 1.84 mm and 3.90 ± 0.75 mm, respectively. Overall satisfaction and ability scores after treatment were higher (p > 0.05) compared with scores prior to the periodontal intervention. Conclusion Periodontal treatment improves masticatory satisfaction and ability with no effect on performance.

Factors Influencing the Changes in Masticatory Performance: The Suita Study

Introduction:

Although previous studies have identified various factors related to masticatory performance, which factors affect longitudinal changes in masticatory performance have not been clarified.

Objectives:

We aimed to clarify factors involved in changes to masticatory performance and construct models from factors related to masticatory performance in a longitudinal study of a general urban population in Japan.

Methods:

A total of 1,005 Japanese subjects (411 men, 594 women; mean age at baseline, 65.7 ± 7.7 years; mean follow-up period, 5.0 ± 0.9 years) were included in the Suita study. These subjects participated in dental checkups both at baseline (June 2008–December 2011) and at follow-up (June 2013–January 2017). The number of functional teeth and occlusal support areas was recorded and the latter assessed using the Eichner index. Subjects’ periodontal status was evaluated based on the Community Periodontal Index. Masticatory performance was determined using test gummy jelly. Factors affecting masticatory performance at follow-up and the degree of their effect were investigated by multiple linear regression analysis.

Results:

In multiple linear regression analysis with masticatory performance at follow-up as the dependent variable, baseline age, masticatory performance, number of functional teeth, and maximum bite force were significant independent variables. The results of multiple linear regression analyses by occlusal support at baseline identified only maximum bite force at baseline in subjects who were Eichner A and baseline age, masticatory performance, and number of functional teeth in subjects who were Eichner B as significant independent variables concerning masticatory performance at follow-up.

Conclusion:

Our study showed a relationship between longitudinal changes in masticatory performance and age, number of functional teeth, and maximum bite force and furthermore showed that the effects of these factors vary according to the residual number of occlusal support areas.

Knowledge Transfer Statement:

Patients and clinicians should recognize the importance of objective and quantitative assessment for chewing efficiency and understand that various factors are related to longitudinal changes in masticatory performance. The results of this study can provide basic data for preventing or improving the decline in masticatory performance for elderly people with varying numbers of occlusal support areas.

Influence of time and different tooth widths on masticatory efficiency and muscular activity in bilateral free-end saddles

PURPOSE

To evaluate the influence of time on masticatory efficiency and muscular activity during mastication of different types of test foods in participants fitted with a lower bilateral free-end saddle removable partial denture (RPD) with wide or narrow teeth.

METHODS

Thirty-six participants consented to undergo evaluation of their masticatory efficiency and recording of their muscular activity, while they wore an RPD with a unified bilateral design, during mastication of different types of test foods. The width of the artificial teeth was changed as follows. Initially (A), the length was adjusted so that the distal end of the mandibular second molars occluded with the distal end of the maxillary second molar (buccolingual width of 7-8 mm). Next (B), the width was decreased to half the maxillary second molars (buccolingual width of only 5 mm). A statistical analysis was performed using SAS software. One-way analysis of variance (ANOVA) was performed followed by Duncan's multiple range tests.

RESULTS

At the 2-month follow-up visit, wider teeth demonstrated greater masticatory efficiency than narrower teeth. However, after 4 months, no significant differences were observed between the two tooth widths. No significant differences in muscular activity were observed.

CONCLUSION

A reduction of the occlusal table width in free-end saddle RPDs resulted in decreased masticatory efficiency 2 months after denture fabrication, but there was no significant difference in muscular activity between narrow and wide teeth. However, after 4 months, the masticatory efficiency of the participants with narrower teeth improved without any changes in muscular activity.

Masticatory efficiency and muscular activity in removable partial dental prostheses with different cusp angles

STATEMENT OF PROBLEM

The loss of posterior teeth has a negative effect on the masticatory efficiency and activity of mastication muscles. How these muscles are affected by partial removable dental prostheses (PRDPs) with different cusp angles is unknown.

PURPOSE

The purpose of this clinical study was to evaluate the influence of different cusp angles, with anatomic (33 degrees), semianatomic (20 degrees), and nonanatomic teeth (0 degree), on the masticatory efficiency and muscular activity of participants receiving mandibular bilateral distal PRDPs.

MATERIAL AND METHODS

Fifteen participants consented to the evaluation of masticatory efficiency and electromyographic (EMG) activity with a PRDP with a unified bilateral design. The cusp angles of the artificial teeth were randomly changed from anatomic (33 degrees), semianatomic (20 degrees), and nonanatomic teeth (0 degree). Masticatory efficiency was evaluated by recording 5 parameters, including number of strokes, and time of mastication while the EMG activities of the masseter and temporalis muscles, measured using surface electromyography. The data were analyzed with 1-way ANOVA and the Tukey multiple post hoc test with statistical software (α=.05).

RESULTS

With regard to masticatory efficiency, PRDPs with anatomic and semianatomic teeth exhibited higher masticatory efficiency than those with nonanatomic teeth, whereas no significant differences were found between PRDPs with anatomic and semianatomic teeth. With respect to EMG activity, the least EMG activity was observed in PRDPs with anatomic teeth, whereas the highest activity was observed with nonanatomic teeth. No significant differences were found between the effect of PRDPs with anatomic and semianatomic teeth on masseter activity.

CONCLUSIONS

Changing the cusp angle from 33 to 20 degrees in PRDPs did not influence the masticatory efficiency or the EMG activity of the masseters. However, it did lead to increased EMG activities of the temporalis muscle. PRDPs with nonanatomic teeth were associated with a significant decrease in masticatory efficiency accompanied by a significant increase in EMG activity.

Cross-sectional association between physical strength, obesity, periodontitis and number of teeth in a general population

AIM

Muscle strength declines and gums recede with increasing age across the life course. Possible associations exist between handgrip strength as an indicator of physical fitness and periodontitis and number of teeth.

MATERIAL AND METHODS

Handgrip strength (GS), anthropometric measures, clinical attachment loss, number of teeth, C-reactive protein and glycated haemoglobin were assessed in 2089 participants of the Study of Health in Pomerania (SHIP-2). Linear regression including interaction with age was used to estimate the association between clinical attachment level, number of teeth and GS.

RESULTS

In multiple regression adjusted for age, body mass index (BMI) and waist-to-hip ratio (WHR) each mm of diminished periodontal attachment was associated with reduction in GS by 1.47 kg (95% CI -2.29 to -0.65) and 0.38 kg (-0.89 to 0.14) in men and women respectively. Correspondingly, each additional remaining tooth was significantly associated with higher GS. Using handgrip strength relative to BMI as outcome, these relationships become even more apparent. Indicators of obesity such as BMI and WHR associated with both GS and periodontitis modulate the relationship between GS and periodontitis with a different impact between the sexes.

CONCLUSION

Periodontitis is associated with GS modified mainly by anthropometric measures related to adiposity and inflammation. Putative mechanisms encompass interactions of factors declining with increasing age.

A multifactorial model of masticatory performance: the Suita study

Previous studies have identified various factors related to masticatory performance. This study was aimed to investigate variations and impacts of factors related to masticatory performance among different occlusal support areas in general urban population in Japan. A total of 1875 Japanese subjects (mean age: 66·7 years) were included in the Suita study. Periodontal status was evaluated using the Community Periodontal Index (CPI). The number of functional teeth and occlusal support areas (OSA) were recorded, and the latter divided into three categories of perfect, decreased and lost OSA based on the Eichner Index. Masticatory performance was determined by means of test gummy jelly. For denture wearers, masticatory performance was measured with the dentures in place. The multiple linear regression analysis showed that, when controlling for other variables, masticatory performance was significantly associated with sex, number of functional teeth, maximum bite force and periodontal status in perfect OSA. Masticatory performance was significantly associated with number of functional teeth, maximum bite force and periodontal status in decreased OSA. In lost OSA, masticatory performance was significantly associated with maximum bite force. Maximum bite force was a factor significantly influencing masticatory performance that was common to all OSA groups. After controlling for possible confounding factors, the number of functional teeth and periodontal status were common factors in the perfect and decreased OSA groups, and only sex was significant in the perfect OSA group. These findings may help in providing dietary guidance to elderly people with tooth loss or periodontal disease.

Does the utilization of dental services associate with masticatory performance in a Japanese urban population?: the Suita study

There are numerous reports on the relationship between regular utilization of dental care services and oral health, but most are based on questionnaires and subjective evaluation. Few have objectively evaluated masticatory performance and its relationship to utilization of dental care services. The purpose of this study was to identify the effect of regular utilization of dental services on masticatory performance. The subjects consisted of 1804 general residents of Suita City, Osaka Prefecture (760 men and 1044 women, mean age 66.5 ± 7.9 years). Regular utilization of dental services and oral hygiene habits (frequency of toothbrushing and use of interdental aids) was surveyed, and periodontal status, occlusal support, and masticatory performance were measured. Masticatory performance was evaluated by a chewing test using gummy jelly. The correlation between age, sex, regular dental utilization, oral hygiene habits, periodontal status or occlusal support, and masticatory performance was analyzed using Spearman's correlation test and t-test. In addition, multiple linear regression analysis was carried out to investigate the relationship of regular dental utilization with masticatory performance after controlling for other factors. Masticatory performance was significantly correlated to age when using Spearman's correlation test, and to regular dental utilization, periodontal status, or occlusal support with t-test. Multiple linear regression analysis showed that regular utilization of dental services was significantly related to masticatory performance even after adjusting for age, sex, oral hygiene habits, periodontal status, and occlusal support (standardized partial regression coefficient β = 0.055). These findings suggested that the regular utilization of dental care services is an important factor influencing masticatory performance in a Japanese urban population.