A multifactorial model of masticatory performance: the Suita study

Efficacy of wireless sensors in assessing occlusal and bite forces: A systematic review

BACKGROUND

The noteworthy correlation between bite force and masticatory performance emphasizes its significance as a meaningful and objective method for assessing oral function. Furthermore, in the study of bruxism, the measurement of intraoral bite force assumes critical importance. Given the importance of assessing occlusal forces and bite force, this systematic review aims to assess the efficacy of wireless sensors in measuring these forces.

METHODS

The search methodology employed in this systematic review adhered to the guidelines outlined by PRISMA. The strategy involved the exploration of various databases, including PubMed/MEDLINE, SCOPUS and SCIELO. An assessment tool was employed to evaluate the bias risk and study quality.

RESULTS

This systematic review encompassed six prospective clinical studies involving a total of 89 participants. Wireless sensors for measuring occlusal forces and bite forces were predominantly employed in healthy adults or individuals with bruxism, along with children undergoing orthodontic treatment. All wireless sensors employed in the studies underwent validation and reproducibility assessments, affirming their reliability. The findings indicated that all wireless sensors exhibited efficacy in detecting occlusal forces and bite forces.

CONCLUSION

Wireless sensors offer real-time monitoring of occlusal and bite forces, aiding in understanding force distribution and identifying bruxism patterns. Despite limited studies on their application, these sensors contribute to evolving insights. Integration into clinical practice requires careful consideration of factors like calibration and patient compliance. Ongoing research is crucial to address limitations and enhance the efficacy of wireless sensors in measuring occlusal and bite forces and managing bruxism.

Evaluation of the Association of Chewing Function and Oral Health-Related Quality of Life in a Population of Individuals Aged ≥ 45 Years and Residing in Communities in Switzerland: A Cross-Sectional Study

PURPOSE

To analyse the association of masticatory performance and oral health-related quality of life in a representative population of individuals residing in communities in Switzerland aged ≥ 45 years.

MATERIALS AND METHODS

In total, 100 subjects completed two dedicated and validated questionnaires on their demographic data and the Geriatric Oral Health Assessment Index. A mixing ability test was performed for assessing masticatory performance. The qualitative analysis of the test was performed by categorizing the images into five categories, while the quantitative analysis was performed via a validated custom-made software.

RESULTS

Sixty-six samples could be analysed. Participants younger than 65 years of age showed significantly less frequent chewing deficiencies (17%) compared to those 65 years and older (50%, p < 0.01). However, retired participants had chewing deficiencies significantly more frequently (8%) compared to workers (51%, p < 0.01). A statistically significant positive association of having chewing deficiency was found between employment status (p < 0.01) and the presence of restorations (p = 0.04), while GOHAI did not show any statistically significant association. Overall, the enrolled subjects displayed moderate chewing function. Masticatory performance was positively associated with the number of present restorations.

CONCLUSIONS

The enrolled subjects residing in communities in Switzerland aged ≥ 45 years displayed moderate chewing function. Their masticatory performance was positively associated with the number of present restorations but not associated with oral health related quality of life (GOHAI).

Reliability between the two-colour chewing gum and the gummy-jelly tests used for the assessment of masticatory performance

OBJECTIVE

This study aimed to evaluate the reliability of two methods used to assess masticatory performance and attempt to correlate them to achieve interchangeability between the methods.

METHODS

Twelve healthy dentate volunteers (men = 6, women = 6; mean age = 28.3 ± 4.1) with no known dental or medical pathologies were requested to participate in this study. Each participant completed three masticatory performance assessments, including two two-colour mixing-ability tests using chewing-gums (CG: gum#1 and gum#2) and the gummy-jelly (GJ) test. For each method, participants created five samples each (total = 15 measurements per participant, gum#1 = 5, gum#2 = 5, GJ = 5). For the gum#1 and gum#2 methods, the predetermined chewing cycles were fixed at 10, 15, 20, 25 and 30 cycles, and for the GJ method, the time duration was fixed at 10, 15, 20, 25 and 30 s. The parameter measures were submitted to Z-score transformation, and Bland-Altman plots were generated to graphically compare the differences between two techniques against their means. Additionally, mountain plot was used to assess the cumulative distribution of measurement error between the methods.

RESULTS

A total of 180 measurements were recorded. There were significant correlations between the number of chewing cycles/chewing time and masticatory performance using the gum#1 (r = -.753; p < .001), gum#2 (r = -.838; p < .001) and GJ (r = .730). When all tests were considered together for each method, significant correlations were found (p < .001). A descriptive range of mean values aiming to produce reference value ranges for predictive purposes was achieved considering the interchangeably among the methods [CG = GJ (VoH-mg = dL): 10 cycle = 10 s: 0.329 = 110; 15 cycles = 15 s: 0.177 = 164; 20 cycles = 20 s: 0.130 = 205; 25 cycles = 25 s: 0.086 = 200; 30 cycles = 30 s: 0.077 = 267].

CONCLUSION

The strong correlations and high consistency between the two masticatory performance methods found in this study conclude that the two assessment methods are reliable and interchangeable. Further evaluations are warranted to arrive at a conversion formula for translation of the results between the two methods.

Development of the Food Acceptance Questionnaire for Thai Partial and Complete Edentulism

This study aimed to develop the Food Acceptance Questionnaire (FAQ) to assess the masticatory ability of Thai older adults (≥60 years). Fifty participants were interviewed using open-ended questions about food they regularly consumed and avoided due to difficulty chewing. From a list of 140 items, 100 were recruited for a trial version of the FAQ. A total of 154 participants responded to the 5-point Likert scale on their chewing perception of each food item (1, impossible to chew; 5, most easily eaten). The average response of each food item was used as the chewing index (CI). The 100 food items were ranked and divided into five grades based on their CIs. Masticatory performance (MP) was objectively assessed by a visual scoring method using gummy jelly (UHA Mikakuto). Two foods from each grade that demonstrated the highest correlation with MP were selected to form the final 10-item FAQ. The FAQ score was calculated by summarizing the responses of 10 items. MP correlated strongly with the FAQ score (r = 0.57, p < 0.001), indicating its predictive validity. Furthermore, the FAQ indicates strong internal consistency (Cronbach's alpha coefficient = 0.90), indicating high reliability. In conclusion, this newly developed 10-item FAQ is valid and reliable for assessing the masticatory ability of Thai older adults.

Laboratory Validation of a Novel Indigenously Developed Bite Force Measuring Device

INTRODUCTION

It is critical to measure the maximum voluntary bite force of patients receiving restorative dentistry. A new device known as "BYTE" has been developed indigenously to measure bite force in humans. The purpose of this study is to evaluate the BYTE device's consistency and accuracy in a lab setting.

METHODOLOGY

Testing and calibration were done in the laboratory. The calibration machine with load cell pressed the biting part of the device with various forces from 3 N to 444 N in 3 N increments for two to three seconds each. The recorded force value in Newton by the device was noted down.

RESULTS

At numerous standard loads, the minimum accuracy error is 0.333 N, while the maximum is 1.667 N. It marginally underestimates the load with an average accuracy error of 0.833 N.

CONCLUSION

The calibration report showed that the BYTE device is precise and reliable and can be used to measure maximum bite force.

Factors related to subjective evaluation of difficulty in chewing among community-dwelling older adults

AIM

Awareness of difficulty chewing may limit the diversity of food intake in older adults. However, few studies have clarified which factors are related to subjective difficulty in chewing. The aim was to identify factors related to subjective difficulty in chewing in 70- and 80-year-old Japanese older adults.

METHODS

A total of 1680 participants (792 men, 888 women) were surveyed. Difficulty in chewing was assessed with questionnaires regarding food intake, such as rice, apples, beef, and hard rice crackers. The participants were classified into two groups, the "with difficulty" group (participants who answered "cannot eat," "can eat with difficulty," and "can eat if small") and the "without difficulty" group (participants who answered "can eat without problems"), according to their answers to questionnaires for each food. A logistic regression analysis with subjective difficulty in chewing as the dependent variable was performed for each food.

RESULTS

Subjective difficulty in chewing was associated with age, occlusal force, and depression for rice; age, number of remaining teeth, occlusal force, and depression for apples; number of remaining teeth, occlusal force, and depression for beef; and number of remaining teeth and occlusal force for hard rice crackers.

CONCLUSIONS

Age, number of remaining teeth, and occlusal force, as well as depression, might be related to subjective evaluation of difficulty chewing in community-dwelling Japanese older adults. Geriatr Gerontol Int 2024; 24: 327-333.

Unveiling the Influence of the Curve of Spee on Bite Force and Chewing Ability: A Comparative Study

Aim

To investigate the impact of the curve of Spee (CS) accentuation on bite force, chewing ability, and additionally, other factors that influence chewing ability and bite force such as restorations, caries, gender, habits, and TMJ problems.

Materials and Methods

231 participants (118 male and 113 female, mean age = ±27.96 years) were recruited for this cross-section study. Participants completed a data collection sheet in which age, gender, Angle's classification of malocclusion, overjet, overbite, TMJ problems, habits, restorations, and caries experience were recorded. Two examiners made a lower impression, chewing ability test and measured the bite force for each participant. Measurement of the CS was obtained digitally from the poured dental cast, and the categorization was as follows: flat (<1 mm), normal (1-2 mm), or deep (>2 mm).

Results

The mean maximum bite force (MBF) was 468.722 N for participants with flat CS, 389.822 N for normal CS, 647.08 N for deep CS, and 384.667 N for reverse CS. The average MBF was higher for participants with deep CS (p < 0.05). MBF force was higher in males. However, BMI was not significantly related to MBF values. Participants with normal and flat CS have comparable chewing capacity (p > 0.05). Also, a significant difference in bite force and chewing ability was found between the three categories of CS (p < 0.05).

Conclusion

Bite force variations across various CS types were linked to gender and habits. Chewing ability showed no differences concerning gender, habits, TMJ problems, caries, or restorations, emphasizing CS's significant impact on bite force while showcasing the unchanged nature of chewing ability amidst diverse factors.

Association Between Reduced Posterior Occlusal Contact and Alzheimer's Disease Onset in Older Japanese Adults: Results from the LIFE Study

BACKGROUND

An association between poor oral health and cognitive decline has been reported. Most of these studies have considered the number of teeth as a criterion, only a few studies have analyzed the relationship between occlusal status and Alzheimer's disease (AD).

OBJECTIVE

To elucidate whether posterior occlusal contact is associated with AD, focusing on the Eichner classification, among an older population aged 65 years or older in Japan.

METHODS

This study used monthly claims data of National Health Insurance in Japan from April 2017 to March 2020. The outcome was newly diagnosed AD defined according to ICD-10 code G30. The number of teeth was estimated by dental code data, and occlusal contact was divided into three categories, namely A, B, and C, according to the Eichner classification. Multivariate Cox proportional hazards models were used to analyze the association between a new diagnosis of AD and the Eichner classification.

RESULTS

A total of 22,687 participants were included, 560 of whom had newly diagnosed AD during a mean follow-up period of 12.2 months. The AD participants had a lower proportion of Eichner A and a higher proportion of Eichner C. After adjusting for covariates, hazard ratios (95% confidence intervals) with Eichner B and C were 1.34 (1.01-1.77) and 1.54 (1.03-2.30), respectively.

CONCLUSION

In older people aged≥65 years old, reduced posterior occlusal contact as well as tooth loss have an impact on AD. This study emphasizes the importance of paying attention to occlusal contacts to reduce the risk of AD.

The relationship between changes in occlusal support and masticatory performance using 6-year longitudinal data from the SONIC study

OBJECTIVES

Reduced occlusal support is thought to be related to a decline in masticatory performance. However, previous research in this field was based on cross-sectional studies. In this study, we conducted a 6-year longitudinal observation of older adults living in the community and examined the associations of changes in occlusal support with masticatory performance.

METHODS

Of the 864 participants aged 72-74 years in the SONIC study, 488 who were followed up (median follow-up period 5.92 years) and had no missing data were included in this study. Participants were divided into three groups according to the number of occlusal support zones in the posterior area: Complete occlusion (four zones), Reduced occlusion (one to three zones), and Collapsed occlusion (no occlusal support zone). Longitudinal analysis of the relationship between occlusal support and masticatory performance was undertaken with linear mixed-effects models.

RESULTS

Sex, occlusal force, number of unreplaced missing teeth, aging, and occlusal support change were significantly related to masticatory performance. Furthermore, the interaction term between change in occlusal support and aging was a significant explanatory variable for the decline in masticatory performance. The interaction was strongest in the group that changed from Complete or Reduced occlusion to Collapsed occlusion. This result indicates that the loss of occlusal support is a major factor contributing to declining masticatory performance.

CONCLUSIONS

The decline of occlusal support was greatly associated with the deterioration of masticatory performance. Our results suggest that older adults need to prevent the collapse of posterior occlusal support to maintain their masticatory performance.

CLINICAL SIGNIFICANCE

Occlusal support is important for preserving masticatory performance in older adults. Preventing the loss of molars and retaining occlusal support may contribute to maintaining food intake diversity and nutritional status, thereby improving quality of life. Dental professionals need to carefully examine dental status to assess the risk of occlusal collapse.

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.

Effect of mandibular bilateral distal extension denture design on masticatory performance

PURPOSE

Removable partial dentures have a wide range of applications as missing tooth prostheses, and the denture design can be quite diverse. However, the factors affecting masticatory function remain unclear. We investigated the effect of denture design, especially the use of indirect retainers and major connectors, on masticatory function in patients with mandibular bilateral distal extension dentures.

METHODS

Fifty-three patients with mandibular Kennedy Class I and Eichner classification B occlusal support were included in this study. Masticatory performance (MP) was assessed using gummy jelly. For the dentures, the type of major connector (bar or apron), presence or absence of indirect retainers, number of rests, and number of artificial teeth were evaluated. The number of functional teeth and occlusal support, Eichner classification, maxillary denture usage, mandibular residual ridge height, and duration of denture use were also evaluated. The factors influencing on the MP were evaluated using the Mann-Whitney U test, Spearman's correlation coefficient, and logistic regression analysis.

RESULTS

MP was significantly higher when the major connector was bar-type or when there was an indirect retainer than with an apron-type or no indirect retainer. MP was positively correlated with the number of functional teeth, occlusal support, and number of rests. Logistic regression analysis revealed that the number of functional teeth and the presence or absence of an indirect retainer were factors that significantly influenced the MP.

CONCLUSIONS

An indirect retainer setting is useful for achieving good masticatory performance in mandibular bilateral distal extension dentures.

Factors related to masticatory performance in patients with removable dentures for jaw defects following oral tumor surgery

Purpose In the treatment of oral tumors, extensive jaw defects due to surgical resection can reduce masticatory performance. Herein, we aimed to clarify the factors related to masticatory performance in patients with jaw defects.Methods In total, 76 patients (42 male and 34 female) underwent prosthetic treatment with a removable denture for a jaw defect following oral tumor surgery. Data on history of radiation therapy, period of time since surgery, period of use of the present denture, number of remaining teeth, and site of the jaw defect were collected. Masticatory performance was evaluated using test gummy jelly. In addition, maximum bite force, tongue pressure, tongue-lip motor function (oral diadochokinesis /pa/, /ta/, /ka/), and oral dryness were evaluated. Logistic regression analysis was performed with lower masticatory performance scores as the dependent variable. Since multicollinearity was suspected between the oral diadochokinesis /ta/ and /ka/ syllables, two logistic regression analyses were conducted: Model 1 with the /ta/ syllable as an explanatory variable, and Model 2 with the /ka/ syllable as an explanatory variable.Results In Model 1, a history of radiation therapy, maximum bite force, number of remaining teeth, tongue pressure, and oral diadochokinesis /ta/ were significant explanatory variables. In Model 2, a history of radiation therapy, maximum bite force, number of remaining teeth, and tongue pressure were significant explanatory variables.Conclusions A history of radiation therapy, maximum bite force, tongue pressure, number of remaining teeth, and motor function of the proglossis are related to decreased masticatory performance in patients with jaw defects.

Comprehensive Analyses of Masticatory Function in Maxillectomy Patients with Functioning Removable Prostheses: A Retrospective Cross-Sectional Study

The aim of this retrospective cross-sectional study was to comprehensively assess masticatory function in maxillectomy patients with functioning removable prostheses. Their general and oral profiles, the measurement values of their oral functions, including masticatory function, and the history of tumor therapy were extracted from medical charts. The correlations of masticatory function with numerical data and the effects of tumor therapy-related factors on masticatory function were evaluated. In addition, a stepwise conditional logistic regression analysis was performed to identify the potential predictive factors comprehensively. The data from 55 maxillectomy patients revealed that the median value of masticatory function (138.0 mg/dL) was higher than the threshold (100.0 mg/dL) based on the concept of oral hypofunction. Moderate correlations of masticatory function with the number of remaining teeth, the number of functioning occlusal supports, and maximum occlusal force were found, as well as a weak correlation with maximum tongue pressure. These variables also showed statistically significant coefficients (p < 0.01). No significant effect of each tumor therapy-related factor on masticatory function was detected. A logistic regression analysis identified the number of functioning occlusal supports as a significant predictive factor. These results implied the crucial interactions of masticatory function with various factors and the specificities of maxillectomy patients.

Association of low occlusal force as an oral hypofunction with the prevalence of irritable bowel syndrome in Japanese adults

BACKGROUND AND AIM

We investigated whether oral-dental conditions may be associated with the prevalence of irritable bowel syndrome (IBS) in a cross-sectional study in Japan.

METHODS

Information on lifestyle and abdominal symptoms was collected, and oral-dental examinations were performed from 2013 to 2017. To investigate the association between oral-dental conditions and IBS, this study used logistic regression analyses adjusted for relevant confounding factors, such as age, sex, BMI, stress, and eating between meals.

RESULTS

The prevalence of IBS was 484 (13.4%) among 3626 participants. The mean maximum occlusal force in the IBS group was significantly lower than that in the non-IBS group (0.306 ± 0.192 kN vs. 0.329 ± 0.205 kN, P = 0.014). The maximum occlusal force of the constipation-type IBS was significantly lower than that of other types of IBS without constipation type (0.269 ± 0.164 kN vs. 0.317 ± 0.198 kN, P = 0.010). Compared with those who had high values of maximum occlusal force (≧0.265 kN), those with a low value of maximum occlusal force (<0.265 kN) had a significantly greater risk for IBS (OR, 1.426; 95% CI, 1.135-1.792; P = 0.002), by multivariate analyses, across different categories of oral-dental condition in women, not in men. Women who had lowest third occlusal force (<0.206 kN) had approximately 35% significantly greater odds of having IBS compared with those who had highest third occlusal force (≧0.386 kN).

CONCLUSIONS

Results suggest that a reduction in the maximum occlusal force increases the risk of IBS in Japanese women.

Neuromuscular and occlusion analysis to evaluate the efficacy of three splints on patients with bruxism

OBJECTIVE

Occlusal splints are always applied on individuals with bruxism to reduce tooth wear and relieve orofacial symptoms such as myofascial pain. The stomatognathic system is mainly composed of tooth, occlusion, masticatory muscles, and temporomandibular joint. The occlusion and masticatory muscles function are regarded as the important parameters for evaluating the stomatognathic system state objectively. However, the effects of occlusal splints on individuals with bruxism is rarely elucidated from accurate neuromuscular analysis and occlusion evaluation. The aim of the present study was to estimate the effects of three different splints (two clinically common full coverage occlusal splint and an modified anterior splint) on subjects with bruxism using K7-J5 neuromuscular analysis system and Dental Prescale II (DP2) to evaluate occlusion.

METHODS

Sixteen subjects claimed to be suffering from nocturnal bruxism,with complete dentition and stable occlusal relationship, were selected for study.The intermaxillary space and the baselines of EMG-activity of the anterior temporalis and masseter were recorded for all the subjects. The participants was treated with three different splints, and outcomes were estimated by comfort index, occlusion and surface electromyography of anterior temporalis and masseter.

RESULTS

At teeth clenched position, EMG data were significantly lower in the participants with use of modified anterior splint than with hard, soft occlusal splint or without splint (p < 0.05). The maximum bite force and bite area occur in subjects without use of splint, while the minimal occur in subjects with use of modified anterior splint. Intermaxillary space increased and masticatory muscles presented significant reduction of EMG data at rest position as a result of J5 (p < 0.05).

CONCLUSION

Modified anterior splint seems to be more comfortable and effective in reducing occlusion force and electromyographic activity of anterior temporalis and masseter for subjects with bruxism.

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.

Relationship between age and occlusal force in adults with natural dentition

This study aimed to clarify the relationship between age and occlusal force in adults with natural dentition. A total of 385 adults (180 males and 205 females) with natural dentition participated in this study. Subjects were asked to perform maximum clenching for approximately 3 s, and the occlusal forces on both sides and habitual chewing side were calculated using a dental prescale. Regression analysis was performed by sex with occlusal forces on both sides and habitual chewing side as the dependent variable and age as the independent variable. In addition, all subjects were divided into three groups: young group (20-39 years), middle group (40-59 years), and old group (60 years and over), and the occlusal forces on both sides and habitual chewing side were compared among the three groups. The occlusal forces did not differ from 20 to 60 years old for both males and females, and the occlusal forces gradually decreased after 60 years old. The curve of the polynomial equation was the most suitable. The occlusal forces on both sides and the habitual chewing side were similar in the young and middle groups, and the values of the old group were significantly smaller than those of the other two groups. From these results, it was suggested that the occlusal force of adults with natural dentition does not differ from 20 to 60 years old and can be represented by a curve of a cubic polynomial, and it significantly decreases after 60 years old.

Clinical and Technical Validation of Novel Bite Force Measuring Device for Functional Analysis after Mandibular Reconstruction

Bite force measuring devices that are generally suitable for edentulous patients or patients undergoing mandibular reconstruction are missing. This study assesses the validity of a new bite force measuring device (prototype of loadpad^®, novel GmbH) and evaluates its feasibility in patients after segmental mandibular resection. Accuracy and reproducibility were analyzed with two different protocols using a universal testing machine (Z010 AllroundLine, Zwick/Roell, Ulm, Germany). Four groups were tested to evaluate the impact of silicone layers around the sensor: no silicone ("pure"), 2.0 mm soft silicone ("2-soft"), 7.0 mm soft silicone ("7-soft") and 2.0 mm hard silicone ("2-hard"). Thereafter, the device was tested in 10 patients prospectively who underwent mandibular reconstruction using a fibula free flap. Average relative deviations of the measured force in relation to the applied load reached 0.77% ("7-soft") to 5.28% ("2-hard"). Repeated measurements in "2-soft" revealed a mean relative deviation of 2.5% until an applied load of 600 N. Maximum bite force decreased postoperatively by 51.8% to a maximum mean bite force of 131.5 N. The novel device guarantees a high accuracy and degree of reproducibility. Furthermore, it offers new opportunities to quantify perioperative oral function after reconstructive surgery of the mandible also in edentulous patients.

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).

Factors Associated with Selection of Denture Adhesive Type: A Cross-Sectional Survey

The type of denture adhesive, cream or home-liner, chosen by regular denture adhesive users and oral conditions contributing to this selection require elucidation. The factors associated with denture adhesive selection were investigated through a face-to-face survey on oral and denture conditions. Age, sex, oral moisture, masticatory performance, retention and stability of the removable denture, ridge shape, mucosal thickness, and duration of denture use were examined in cream and home-liner-type denture adhesive users who did not regularly visit a dentist. Univariate analysis and multivariate analyses were performed. There were 38 and 40 cream-type and home-liner-type adhesive users, respectively. The type of denture adhesive was significantly associated with the oral moisture value, retention, ridge shape, mucosal thickness, and duration of denture use in univariate analyses. The residual ridge conditions with large factor loadings for ridge shape and mucosal thickness and duration of denture use were significantly related to the denture adhesive selection in multivariate logistic analysis. The residual ridge conditions and duration of denture use were significant factors in the selection of cream- and home-liner-type denture adhesives. These results can provide appropriate guidance based on the adhesives patients without dental supervision are more likely to choose.

Maria MT, Marito P, Takano H, Khaing AMM, Nokubi T, Ono T. Masticatory Performance Test Using a Gummy Jelly for Older People with Low Masticatory Ability

Evaluation of masticatory ability has become more important in an aging society because decreased masticatory ability has the potential to affect the general health of older people. A new masticatory performance test, intended for older people with low masticatory ability, has been developed using gummy jelly half the size of that used in the conventional masticatory performance test. This study aimed to investigate the compatibility between the new and conventional tests and the adaptation of the new test. The new test using the 8-grade visual score with half-size gummy jelly was performed among 137 removable denture wearers (mean age 75.8 ± 9.0 years) with low masticatory performance (a score of ≤4 on a conventional test). The correlation between the scores of half-size gummy jelly (VS-H) in the new test and those of full-size gummy jelly (VS) in the conventional test was evaluated. VS-H among the groups divided by VS were also compared. A strong positive correlation was detected between VS-H and VS (r_s = 0.70). In groups with VS of 0 and 1, VS-H values were widely distributed from 0 to 7. There were significant differences in VS-H between the groups with VS of 0-2 but no significant differences in VS-H between the groups with VS of 2-4. Therefore, the masticatory performance test using half-size gummy jelly is suitable for a detailed evaluation of masticatory ability in older people with low masticatory ability when their visual score of full-size gummy jelly in the conventional test is 2 or less.

Effective oral function improvement by restoration-driven implant treatment after mandibular resection with a scapular flap: a case report

BACKGROUND

The extensive loss of teeth and surrounding tissues due to mandibulectomy for an oral tumor not only impacts negatively on appearance, but also often causes various functional disorders, decreasing quality of life (QOL). In the present case, reconstruction with a scapular flap was carried out along with segmental mandibulectomy, aiming for functional restoration through restoration-driven implant treatment. A good outcome was obtained, with improvement of masticatory function and QOL following the prosthetic treatment.

CASE PRESENTATION

The patient was a 37-year-old woman diagnosed with ossifying fibroma in the left side of the mandible. Segmental mandibulectomy and reconstruction with a scapular flap were carried out. Implant diagnostic simulation was performed, and based on the result, secondary reconstruction using a particulate cancellous bone and marrow graft was carried out by an oral surgeon. After wound healing was complete, implant placement was performed twice, and the final prosthodontic treatment was completed. Masticatory performance and maximum bite force, which are indices of masticatory function, were improved from before to after prosthetic treatment. In addition, oral health-related QOL was improved from before to after prosthetic treatment.

CONCLUSION

In the present case, restoration-driven implant treatment was performed in a patient following segmental mandibulectomy for a mandibular tumor, with a good outcome. Planning the treatment measures with a focus on the final prosthetic vision can lead to improvement of oral function in patients with extensive mandibular defects.

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.

Decline in Oral Function and Its Management

With the renewed focus on eating abilities in the ageing population, new concepts referred to as oral frailty and oral hypofunction have been introduced in Japan. We aimed to provide an overview of (i) the evaluation and management of oral function in ageing populations according to oral frailty and oral hypofunction and (ii) recent scientific evidence of the associations of poor oral function with physical function and nutritional status. Both oral frailty and oral hypofunction are multidimensional concepts that describe poor oral function. In epidemiologic and/or clinical settings, they are defined as the accumulation of factors leading to poor oral status. Oral hypofunction is a core component of oral frailty. To date, there are no systematic strategies for addressing oral frailty or oral hypofunction. Nevertheless, recent randomised controlled trials revealed that several components of oral function can be improved through appropriate training. On the other hand, multiple observational studies published in recent years have demonstrated that oral frailty and oral hypofunction are associated with physical function (gait performance, frailty, and sarcopenia) and nutritional status (low protein intake, poor dietary diversity, and malnutrition) in community-dwelling older adults. Moreover, studies have reported a significant association between insufficient participation in social networks and poor oral function. However, most of the studies conducted to date have utilised a cross-sectional design, which does not permit assessment of the temporal association between comprehensive oral function and general health. Maintaining good oral function may be key to longevity. However, evidence is limited thus far, and comprehensive oral function has not been studied in detail; thus, additional high-quality studies are needed.

Development a new chewing problem directory and its validation for Korean elders

Objectives

This study aimed to develop a new chewing problem directory (CPD) and validate it with oral health indicators such as total occlusion force, number of natural and rehabilitated teeth (NRT), NRT posterior, natural teeth, natural teeth posterior, and dental status among Korean elders.

Background

Chewing problem is the main oral health problem in elders. However, there has been no validated tool using both subjective and objective assessment of chewing problem.

Subjects and methods

A total of 537 participants aged 65 years or more were randomly assigned into 2 subsamples: developing sample (n = 260) for developing and internally validating the new CPD as the 1st stage and confirmation sample (n = 277) for confirming validation of CPD as the 2nd stage. CPD was developed using three subjective questionnaires (general eating, chewing nuts, and chewing meat problem) and objective NRT. Periodontitis, age, sex, education, smoking, alcohol drinking, metabolic syndrome, and frailty were considered as confounders. Following the development of CPD, CPD was validated using multiple multivariable logistic regression after controlling for confounders in confirmation sample and total sample.

Results

The Cronbach’s alpha value for three subjective questionnaires of CPD was 0.87. Among oral health indicators, NRT (0–28) showed the highest impact association with subjective chewing problem score (partial r = − 0.276). The chewing problem from the new CPD was associated with all items of oral health indicators. The prevalence of chewing problems by CPD was 57.7% in developing sample. Elders with NRT ≤ 24, compared with those with NRT ≥ 25, showed the highest impact on chewing problems by new CPD (Odds Ratio = 7.3 in the confirmation sample and 5.04 in the total sample, p < 0.05) among oral health indicators.

Conclusion

This new CPD was developed as a valid tool to evaluate the chewing problem for Korean elders in dental clinics and community-based settings.

Masticatory dysfunction in patients with diabetic neuropathy: A cross-sectional study

Introduction

Chewing well is essential for successful diet therapy and control of blood glucose level in patients with diabetes. In addition, long-term hyperglycemia is a risk factor for microvascular complications, which are the main cause of morbidity and mortality in these patients. Hence, it is plausible that masticatory disorder may be relevant to diabetic microvascular complications which is caused by long-term hyperglycemia. The aim of this study was to investigate whether masticatory disorders are relevant to diabetic microvascular complications.

Methods

This cross-sectional study included 172 patients with type 2 diabetes who underwent educational hospitalization in the Department of Endocrinology and Diabetic Medicine, Hiroshima University Hospital, from April 2016 to March 2020. Masticatory efficiency was determined quantitatively by using the GLUCO SENSOR GS-Ⅱ. Multivariable linear regression models were constructed to examine which factors were related to masticatory efficiency. Statistical significance was defined as a two-sided p value of < 0.05.

Results

According to the bivariable analysis, masticatory efficiency was significantly correlated with duration of diabetes (p = 0. 049), number of remaining teeth (p < 0.0001), the number of moving teeth (p = 0.007) and condition of diabetic neuropathy (p < 0.0001). Moreover, the number of remaining teeth (p < 0.0001) and diabetic neuropathy (p = 0.007) remained significantly correlated with masticatory efficiency in the multivariable analysis.

Conclusions

For the first time, we demonstrated that patients with type 2 diabetes who developed diabetic neuropathy had significantly reduced masticatory efficiency. Effective mastication is an important factor in successful diet therapy for diabetes. To prevent the progression of diabetic complications, especially in patients with diabetic neuropathy, it may be necessary to combine individualized therapies from dentists and nutritionists with consideration for the level of masticatory dysfunction.

Oral hypofunction and association with need for daily assistance among older adults in long-term care

BACKGROUND

Oral hypofunction (OHF) is related to occlusal status and bite force. It has specific symptoms and varying degrees of severity.

OBJECTIVES

OHF was determined with five signs. The relationships between OHF and need for assistance in oral hygiene, moving, eating, and occlusal status in older adults living in long-term care (LTC) were examined.

METHODS

A comprehensive clinical oral examination was conducted on 393 residents who lived in LTC in Helsinki, Finland. The five signs to determine OHF were mouth dryness, visible food residue on oral or denture surfaces, ability to keep the mouth open during examination, clearness of speech, and diet of pureed or soft food. Score points of 0-2 were given for each sign and the sum was categorized as mild, moderate, or severe OHF. Participants were divided into three groups accordingly, and occlusal status was determined based on contact units. In addition, nurses collected background information on number of medications and level of cognition. Need for assistance was based on oral hygiene, moving, and eating.

RESULTS

Of participants (n=319), 21% showed severe and 41% moderate OHF. Occlusal status differences between the OHF groups were significant. OHF severity associated linearly with increased severity of cognitive impairment and increased need for assistance in oral hygiene, eating, and moving.

CONCLUSIONS

OHF score based on the five signs can be used to determine OHF severity. OHF was common and associated with occlusal status, cognitive impairment, and need for assistance in oral hygiene, moving, and eating in older adults living in LTC.

Tooth Loss Related with Prevalence of Metabolic Syndrome in a General Urban Japanese Population: The Suita Study

We examined whether the number of teeth could be a surrogate marker for metabolic syndrome (MetS) risk in cross-section. A total of 3771 individuals from the general urban Japanese population (1690 men, 2081 women; mean age 67.1 ± 11.0 years) participated in this study. Participants were diagnosed with MetS with three or more components hypertension, hyperglycemia, lipid metabolism abnormality, and abnormal abdominal girth. Questionnaires were administered to determine the number of teeth, smoking status, drinking status, and past illnesses. To clarify the relationships between the number of teeth and the presence of MetS components, we divided subjects into two groups: those with less than 20 residual teeth and those with 20 or more, then statistical analyses (Mantel-Haenszel tests and logistic regression analysis) were performed. MetS were higher for those with ≤19 teeth than those with ≥20 teeth when examining all participants and women-only groups. Hyperglycemia, low HDL cholesterol, high triglycerides, and diagnosis with MetS were all significantly higher in the ≤19 teeth group for both sexes combined and for women. These results suggest that less than 20 teeth may be a surrogate marker for MetS risk, but further studies on gender differences and pathological background are needed.

Gender modified association of oral health indicators with oral health-related quality of life among Korean elders

OBJECTIVE

To evaluate the association between oral health-related quality of life (OHRQoL) and oral health indicators including dental status, total occlusion force (TOF), number of natural and rehabilitated teeth (NRT), number of natural teeth (NT), and to explore the effect modification on the association by gender among Korean elders.

METHODS

A total of 675 participants aged 65 or above recruited by a cluster-based stratified random sampling were included in this cross-sectional study. The 14-items Korean version of the Oral Health Impact Profile (OHIP) was used to measure OHRQoL. The responses about OHIP were dichotomized by the cut-off point of 'fairly often' to determine the 'poor' versus 'fair' OHRQoL. Age, gender, education level, alcohol drinking, smoking, metabolic syndrome, frailty, and periodontitis were considered as confounders. Multiple multivariable logistic regression analyses were applied to assess the adjusted association between oral health indicators and OHRQoL. Gender stratified analysis was also applied to explore the effect modification of the association.

RESULTS

The prevalence of poor OHRQoL was 43.0%, which was higher in women, less-educated elders, alcohol non-drinkers and frailty elders (p < 0.05). Elders with poor OHRQoL also showed lower values of oral health indicators than elders with fair OHRQoL (p < 0.05). Those with NRT ≤ 24, NT ≤ 14, and TOF < 330 N increased the risk of poor OHRQoL by 2.3 times (OR = 2.26, confidence interval [CI] 1.54-3.31), 1.5 times (OR = 1.45, CI 1.02-2.07), and 1.5 times (OR = 1.47, CI 1.06-2.04), respectively. In women, the association of NRT ≤ 24 with poor OHRQoL increased from OR of 2.3 to OR of 2.4, while, in men, the association of TOF < 330 N with poor OHRQoL increased from OR of 1.5 to OR of 3.2.

CONCLUSION

Oral health indicators consisting of TOF, NRT, and NT were independently associated with poor OHRQoL among Korean elders. Gender modified the association of TOF and NRT. Preventive and/or curative management for keeping natural teeth and the rehabilitation of missing teeth to recover the occlusal force may be essential for reducing poor OHRQoL.

Standard Values and Concurrent Validity of a Newly Developed Occlusal Force-Measuring Device among Community-Dwelling Older Adults: The Otassha Study

Recently, an occlusal force-measuring device with a capacitive-type pressure-mapping sensor (OFMD-CPS) was developed. We aimed to establish age- and sex-specific standard values for OFMD-CPS-measured occlusal force (OF) and to assess the concurrent validity of the OFMD against another OF measuring system with a pressure-sensitive sheet (Dental Prescale II). Using data from a population-based study, we calculated the OFMD-CPS-measured OF means and deciles in 5-year age groups for each sex. The OFMD-CPS-measured OF was validated against the Dental Prescale II-measured OF with Spearman correlation coefficients. Furthermore, we calculated the area under the receiver operating characteristic curve (AUC) against the preexisting Dental Prescale II-measured OF cutoff value of 350 N. In total, 596 individuals (236 men and 360 women) with a mean (standard deviation (SD)) age of 73.7 (6.7) years were included in the analyses. The mean (SD) OFMD-CPS-measured OFs were 581.6 (284.6) N in men and 446.9 (209.9) N in women. There was a strong positive correlation (Spearman's Rho = 0.73) between OFMD-CPS-measured and Dental Prescale II-measured OF. The diagnostic accuracy of the OFMD-CPS-measured OF for the Dental Prescale II-measured OF cutoff value was high (AUC = 0.88). In conclusion, we demonstrated standard values and concurrent validity of OFMD-CPS-measured OF in community-dwelling older adults.

Relationship between skeletal bone mineral density and subjective masticatory difficulty

Background

Masticatory ability is an essential factor for sustaining quality of life and social and systemic well-being, particularly in elderly. This study aimed to reveal the association between subjective masticatory difficulty and skeletal bone mineral density (BMD).

Methods

Data from the Korean National Health and Nutrition Examination Survey, which was conducted from 2008 to 2011 were analyzed. This study included 13,092 Koreans (5656 males, 7436 females) over 50 years of age. Masticatory difficulty was evaluated based on a self-reported questionnaire. Areal BMD of the total hip, femoral neck, and lumbar spine as well as lean body mass were determined using dual-energy X-ray absorptiometry. Data about the sociodemographic characteristics, physical activity, number of teeth present, sum of decayed, missing, and filled permanent teeth (DMFT) index and Community Periodontal Index (CPI) were collected. Multivariate logistic regression analysis was conducted to analyze associations between subjective masticatory difficulty and BMD, adjusting for the confounding covariates.

Results

Significant differences were observed in the areal BMD of the total hip, femoral neck, and lumbar spine as well as lean body mass accordance with the presence of subjective masticatory difficulty in both males and females. The number of teeth, DMFT, and CPI score did not show significant differences based on the presence of self-reported satisfaction of chewing performance in both males and females. Results from multivariate logistic regression demonstrated that the subjective masticatory difficulty showed significant interactions with skeletal BMD and the associations between masticatory satisfaction and BMD of the total hip and femoral neck were more prominent in females compared to those in males.

Conclusions

The skeletal BMD, particularly areal BMD of the femoral neck was significantly associated with subjective masticatory difficulty in elderly, especially in elder females.

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.

Capacitive-Type Pressure-Mapping Sensor for Measuring Bite Force

Bite force is an important indicator of masticatory performance. However, existing methods for measuring bite force are either ineffective or expensive. Hence, we developed a novel capacitive-type pressure-mapping sensor that converts mechanical forces into changes in capacitance and calculates bite force. A portable device was fabricated based on this sensor sheet, and the accuracy of the bite-force measurements provided by the device was evaluated. The sensor has a thickness of 1.6 mm and has 63 measurement points. It was inserted into a dental model, where the output value was measured and compared with that of a universal testing machine (AG-IS 100 kN). A regression equation to estimate the bite force was obtained based on the relationship between the output of the capacitive-type pressure-mapping sensor and that of the load cell of the universal testing machine. The estimated bite force from the sensor and the quadratic regression equation closely resembled the known load applied by the compression tester (R² = 0.992). We therefore conclude that the developed sensor can measure bite force accurately and effectively. A device with a built-in capacitive-type pressure-mapping sensor can potentially be a user-friendly tool for bite-force measurements in both clinical and epidemiological settings.

Association of occlusal support with type 2 diabetes: A community-based study

Occlusal support was proved to be associated with type 2 diabetes. Our aim was to investigate the association between the Eichner index and the prevalence of type 2 diabetes. We included 715 participants with oral health examinations in the Shanghai Aging Study. The occlusal support status was determined by the number of functional occlusal support areas and Eichner index classifications. Those with fasting plasma glucose ≥126 mg/dL and/or hemoglobin A1c ≥6.5% and/or current medications for type 2 diabetes with relevant medical history were diagnosed with type 2 diabetes. Multiple logistic regression models were used to analyze the relationship between occlusal support status and type 2 diabetes. The average age of 715 participants was 73.74 ± 6.49 years old. There were 84 diabetics with 1.71 occlusal supporting areas on average. Seven hundred and fifteen participants were divided into 3 groups according to Eichner classifications: Eichner group A with 4 occlusal functional areas, Eichner group B with 1-3 occlusal functional areas or 0 area with anterior occlusal contact, and Eichner group C with no functional occlusal contact. Blood glucose level was significantly lower in participants of Eichner group A compared to those in group B or C. The ordinal logistic regression showed more occlusal supporting areas were significantly associated with less type 2 diabetes cases with an Odds Ratio(OR) of 0.253(95%CI 0.108-0.594) after adjusting covariates. Participants in Eichner group A had a significantly much lower OR of 0.078 for type 2 diabetes (95%CI 0.009-0.694) compared to those in Eichner group C after adjustment. The number of functional occlusal support areas might be inversely related to the blood glucose level and the prevalence of type 2 diabetes.

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.

Reference value of masticatory performance by measuring the amount of glucose extraction from chewing gummy jelly

PURPOSE

The purpose of this study was to determine a reference value for masticatory performance (MP) by measuring the amount of glucose extracted(AGE) from chewing gummy jelly.

METHODS

A total of 237 young adults (young group, 20-39 years), 147 middle-aged adults (middle-aged group, 40-59 years), and 177 older adults (old group, 60-87 years) participated in this study. All participants had natural dentition, excluding the third molars. AGE was measured when the participant chewed gummy jelly and used as a parameter of MP. AGE was compared among the three groups. Next, AGE in each group was compared between the habitual chewing side and non-habitual chewing side, and between males and females. The correlation between age and AGE was also investigated.

RESULTS

AGE in the young, middle, and old groups were similar, and no significant differences were observed. AGE was significantly higher in the habitual chewing side compared to the non-habitual chewing side, and in males than that in females. No significant correlations were found between age and AGE. AGE in the habitual chewing side of all ages was 221.9 ± 34.4 mg/dL for males and 206.0 ± 28.7 mg/dL for females. The mean-2SD (standard deviation) value representing the reference value of healthy adults was 153.1 mg/dL for males and 148.6 mg/dL for females, which was close to 150 mg/dL.

CONCLUSION

It was concluded that the reference value of masticatory performance as measured by the amount of glucose extraction after chewing gummy jelly was 150 mg/dL.

Oral factors and adherence to Mediterranean diet in an older Greek population

PURPOSE

The aim of this study was to investigate the effect of oral factors on adherence to the Mediterranean diet in an older population METHODS: 130 persons over 60 years visiting Open Care Community Centers for Older People participated in this study. Oral interviews recorded demographic and sociomedical information, subjective oral complaints, and dental habits. Adherence to Mediterranean diet was assessed using the MDI_BNC4H index (range: 0-14). An oral examination was performed, and evaluation of the masticatory performance was carried out using a two-color chewing gum that was digitally analysed.

RESULTS

The mean age of the study participants was 73.9 ± 8.5 years. The score of adherence to the Mediterranean diet ranged from 3 to 9 (5.6 ± 1.4). 58 participants used removable prostheses, while 20 used a pair of complete dentures. Univariate analyses revealed that the parameters that negatively significantly, or marginally significantly, affected the level of adherence to the Mediterranean diet were lower masticatory performance (p = 0.050), larger number of drugs per day (p = 0.056), higher BMI (p = 0.043) and smoking (p = 0.053). The multivariable analysis revealed that lower adherence to the Mediterranean diet was significantly associated with higher BMI (p = 0.047) and lower masticatory performance (p = 0.050).

CONCLUSIONS

Increased masticatory performance was an independent predictor of better adherence to the Mediterranean diet in an older population.

Sociomedical and oral factors affecting masticatory performance in an older population

OBJECTIVES

To assess the sociomedical and oral factors affecting masticatory performance in a community-dwelling older population.

MATERIALS AND METHODS

Community-dwelling persons over 60 years were investigated using medical and dental oral interviews, oral and denture examination (natural teeth, tooth mobility, number of occluding tooth pairs, and removable dentures' prevalence and quality), and evaluation of masticatory performance using a mixing ability test.

RESULTS

A total of 130 participants with a mean age of 73.9±8.5 years were recorded. Fifty-eight (44.6%) used various types of removable prostheses. Twenty were edentulous and used a pair of complete dentures. Univariate analyses revealed statistically significant associations (p≤0.05) between masticatory performance and aging, marital status, subjective chewing ability, use of removable dentures, use of various combinations of complete dentures, pain caused by maxillary denture, number of teeth, tooth mobility, posterior chewing pairs, all chewing contacts natural or prosthetic, retention of mandibular partial dentures, and dentures' occlusion. The multivariable quantile regression analysis revealed that fewer natural teeth (95% CI: -0.02-0.01, p<0.001), being edentulous and using a pair of complete dentures (95% CI: 0.09-0.35, p=0.001), and larger percentage of severely mobile teeth (95% CI: 0.07-0.82, p=0.020) were associated with lower masticatory performance.

CONCLUSIONS

Poor masticatory performance in older adults was associated with fewer teeth, being edentulous and using a pair of complete dentures, and increased prevalence of severe tooth mobility.

CLINICAL RELEVANCE

Retaining the natural dentition and preventing and treating periodontal disease are important measures to maintain masticatory performance in older adults.

Nutritional status and body composition in cognitively impaired older persons living alone: The Takashimadaira study

OBJECTIVES

To investigate nutritional status and body composition in cognitively impaired older persons living alone.

METHODS

This cross-sectional study included 1051 older adults (633 women and 418 men, mean age: 77.1 years) from the Takashimadaira study. The study participants were categorized according to whether they lived alone, which was confirmed via questionnaire, and had cognitive impairment, which was defined as having a Mini Mental State Examination-Japanese score ≤23. Nutritional status was evaluated using the serum albumin level. The fat-free mass index (FFMI) was calculated based on anthropometric and body composition measurements. A logistic regression model with the outcome of a low serum albumin level (serum albumin <4 g/dL) and low FFMI (<16 kg/m2 in men and <14 kg/m2 in women) were used to analyze the data.

RESULTS

The percentages of participants in the living alone (-)/cognitive impairment (-) group, the living alone (+)/cognitive impairment (-) group, the living alone (-)/cognitive impairment (+) group, and the living alone (+)/cognitive impairment (+) group were 54.8%, 37.3%, 5.6%, and 2.3%, respectively. Compared to the living alone (-)/cognitive impairment (-) group, the living alone (+)/cognitive impairment (+) group was more likely to have a low serum albumin level (adjusted odds ratio = 3.10, 95% confidence interval = 1.31 to 7.33) and low FFMI (adjusted odds ratio = 2.79, 95% confidence interval = 1.10 to 7.06) after adjusting for potential confounders.

CONCLUSION

Cognitively impaired older adults living alone had poorer nutrition than cognitively normal and cohabitating persons in this study. Our results highlight the importance of paying extra attention to nutritional status for this group of community-dwelling older adults.

The Influence of Age and Oral Health on Taste Perception in Older Adults: A Case-Control Study

Declining gustatory function, nutrition, and oral health are important elements of health in older adults that can affect the aging process. The aim of the present work was to investigate the effect of age and oral status on taste discrimination in two different groups of elderly subjects living either in an Italian residential institution (TG) or in the community (CG). A total of 90 subjects were enrolled in the study (58 CG vs. 32 TG). Masticatory performance (MP) was assessed using the two-color mixing ability test. Taste function was evaluated using cotton pads soaked with six taste stimuli (salty, acid, sweet, bitter, fat and water). A positive correlation between age and missing teeth (r = 0.51, C.I. [0.33; 0.65], p < 0.0001), and a negative correlation between age and MP (r = −0.39, C.I. [−0.56; −0.20], p < 0.001) were found. Moreover, significant differences for salty taste, between TG and CG were detected (p < 0.05). Significant differences in bitter taste sensitivity between subjects wearing removable and non-removable prosthesis were also determined (p < 0.05). In addition, significant gender differences and between males in TG and CG were identified (p < 0.05). The best understanding of the relationship between MP, taste sensitivity, and nutritional factors is a necessary criterion for the development of new therapeutic strategies to address more effectively the problems associated with malnutrition in elderly subjects.

Development of the Sakiika Transport Test: A Practical Screening Method for Patients with Oral-phase Dysphagia

PURPOSE

This study aimed to develop a simple screening test for mastication, "the Sakiika (squid jerky) transport test (STT), which evaluates the vertical jaw movement coordinated with the lateral tongue movement during stage I transport, and investigate the possibility of its clinical application.

METHODS

The study included 73 people with dysphagia (mean age, 78.5 ± 7.8 years; median age, 79.0 years; interquartile range, 75.0-84.0). The STT evaluated the ability of a participant to transport a piece of squid jerky placed on the midline of the tongue to the molar region. The STT score was defined as the number of vertical jaw movements occurring as the tongue transported food to the molars. A cutoff value was set by comparing the STT scores with masticatory function evaluated via a videofluoroscopic swallowing study and with food texture evaluated using the Food Intake LEVEL Scale (FILS).

RESULTS

The STT scores counted by the two examiners had a κ coefficient of 0.79, indicating good reliability. The STT score was significantly associated with both the presence of masticatory movement ( p = 0.019) and food texture classified by FILS ( p = 0.032) at cutoff value of "3" (3 vertical movements). The STT showed 62% sensitivity and 75% specificity for masticatory movements.

CONCLUSION

The STT could be a useful screening test to assess the presence or absence of food transportation to the molars for mastication in older patients with dysphagia. In addition, the STT could be useful in identifying the need to modify food texture to meet functions.

Compatibility of two types of gummy jelly tests for detecting decreased masticatory function

OBJECTIVE

This study aimed to verify the compatibility of masticatory performance tests using different two types of gummy jellies.

BACKGROUND DATA DISCUSSING THE PRESENT STATUS OF THE FIELD

Compatibility between the glucose concentration measuring method (GC) and 10-steps visual scoring method (VS), which are masticatory performance tests for diagnosing decreased masticatory function (DMF) in oral hypofunction and the use of different types of gummy jelly, has yet to be confirmed.

MATERIALS AND METHODS

The participants consisted of 134 Japanese older people (51 men and 83 women). GC, VS and the increased surface area measuring method (ISA), as an alternative analysis method for VS, were conducted to evaluate masticatory performance. Cohen's Kappa coefficient was used to verify the consistency for detecting DMF between GC and VS. Pearson's correlation coefficient was used to analyse the relationship between GC and ISA. Each masticatory performance was compared among three different groups for the number of residual teeth. Cut-off values of VS and ISA for DMF that were consistent with GC were identified.

RESULTS

Glucose concentration measuring method and VS showed an excellent consistency (Kappa coefficient = 0.86). There was a high positive correlation between GC and ISA (r = .70). However, the change in masticatory performance according to the number of teeth was different between GC and VS/ISA. The cut-off values of VS and ISA were a Score of 2 and 1687 mm² , respectively.

CONCLUSION

Glucose concentration measuring method and VS/ISA remained fairly consistent for detecting DMF, which might be useful information to interconnect the various studies on masticatory performance.

Masticatory performance and other oral functions in community-dwelling elderly patients without posterior occlusal support by natural teeth

PURPOSE

To evaluate masticatory performance (MP), maximum occlusal force (MOF), maximum tongue pressure (MTP) and oral diadochokinesis (ODK) among community-dwelling elderly patients without posterior occlusal support.

METHODS

This study enrolled community-dwelling elderly patients (≥65 years old) who belonged to Eichner A, B4, C1, C2, and C3. Each oral function was statistically compared among groups. Correlations between MP and other variables were examined in Eichner B4 and C patients.

RESULTS

MP and MOF values in Eichner B4 and C patients were significantly lower than in Eichner A patients. There were significant differences in MTP values between Eichner "A and C2, C3", and "B4 and C2, C3". ODK in Eichner C patients showed significantly lower values compared to Eichner A patients in general. Although there were statistically significant correlations of MP with age, the number of remaining teeth and all oral functions were identified, and multiple regression analysis indicated that MOF and MTP were independently related to MP.

CONCLUSION

Oral functions in Eichner B4 and C patients were lower compared to Eichner A patients. MP was significantly correlated with MOF and MTP in elderly patients without posterior occlusal support, suggesting the importance of rehabilitation of MOF and MTP in MP.

Risk assessment of lacunar infarct associated with oral conditions: A case control study focused on radiographic bone loss and Eichner classification

PURPOSE

This study aimed to evaluate whether lacunar infarcts can be predicted from occlusal support and periodontal stage on images.

METHODS

Seventy patients with lacunar infarcts and 300 participants without lacunar infarcts who underwent cerebral checkups at our university hospital were retrospectively reviewed. Lacunar infarcts were assessed using magnetic resonance images by a neuroradiologist. The number of teeth, occlusal support, and severity of radiographic bone loss (RBL) were evaluated using computed tomography. Occlusal support was classified according to the Eichner classification. Additionally, patient characteristics were investigated using medical charts and blood test reports. Records of clinical periodontal parameters, such as clinical attachment loss and bleeding on probing, were also evaluated.

RESULTS

The severity of RBL and Eichner classification in patients with lacunar infarcts was significantly higher than that in individuals without lacunar infarcts (P<.01). Receiver operating characteristic analysis revealed that the cut-off values for predicting lacunar infarct were ≥ III in the severity of RBL and ≥B1 in the Eichner classification. The corresponding areas under the curve were 0.75 and 0.70, respectively. In multivariate analysis, the factors affecting the severity of RBL (≥ III) (odds ratio [OR], 8.1; 95% confidence interval [CI], 4.1-16.3; P ‹.001), and Eichner classification ( ≥B1) (OR, 1.9; 95% CI, 0.86-4.1; P ‹.05) were significantly associated with the occurrence of lacun ar infarcts.

CONCLUSIONS

The severity of RBL and the Eichner classification may be helpful in predicting lacunar infarcts. Therefore, proper periodontal treatment and prosthodontic rehabilitation of missing teeth may prevent lacunar infarcts.

Analyses of Swallowing Function and Its Related Factors in Community-Dwelling Elderly Patients: A Case-Control Study

This retrospective case-control study evaluated the prevalence of declined swallowing function and the association with oral functions and gender in community-dwelling elderly patients. Their profiles, the results of swallowing function (Eating Assessment Tool: EAT-10) and other oral functions (oral dryness, maximum occlusal force (MOF), tongue-lip motor function (oral diadochokinesis: ODK), maximum tongue pressure (MTP) and masticatory performance (MP)) were extracted for analyses. The patients were categorized into three groups according to EAT-10 score (Group 1: 0, Group 2: 1 and 2, Group 3: ≥3). In total, 242 patients were enrolled and 46 of them (19.0%) were categorized into declined swallowing function (Group 3). In two-group comparisons (Group 1, 2 versus Group 3), significant differences were identified in age and the number of remaining teeth, but they were not identified in three-group comparisons. The patients with declined swallowing function (Group 3) had significantly lower function in ODK and MTP. Multiple logistic regression analyses identified that declined swallowing function was independently associated with declined functions in ODK /ka/ (OR: 5.31, 95% CI: 1.03-27.23, p = 0.04) and in MTP (OR: 2.74, 95% CI: 1.12-6.66, p = 0.03). This study could confirm the critical role of tongue functions in swallowing in community-dwelling elderly patients.

Inter-measurement variation of masticatory performance test using gummy jelly

The purpose of this study was to clarify the inter-measurement variation of the masticatory performance test. Forty healthy adults were divided into group A (10 males and 10 females), who did not chew the test food before experiment, and group B (10 males and 10 females) who chewed the test food before the experiment. Subjects were asked to chew a gummy jelly for 20 s on the habitual chewing side, and the amount of glucose extraction was measured. The test was repeated three times with an interval of 1 min in both groups (Group A: A1, A2, A3; Group B: B1, B2, B3). In both groups A and B, the difference between the measured values was compared and the reliability between measurements was investigated. In group A, the value of A1 was small, and a statistically significant difference was observed between A1 and other measured values. In group B, the three measured values were similar and no significant difference was observed among the measured values. The intraclass correlation coefficient (ICC) values for determining inter-measurement reliability in group A were 0.758 for A1-A2-A3, 0.708 for A1-A2, and 0.901 for A2-A3. The ICCs in group B were 0.924 for B1-B2-B3, 0.945 for B1-B2, and 0.926 for B2-B3. Based on these results, it can be suggested that high reliability between the measurements can be obtained if the subjects are accustomed to chewing the test food before the experiment, and that the measured values were similar whether it was performed two or three times. Consequently, one measurement was sufficient if subjects were accustomed to chewing the test food before the experiment.

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.

Gender differences in masticatory function in elderly adults with natural dentition

The purpose of this study was to clarify the presence or absence of gender differences in masticatory function in elderly adults with completely natural dentition. Fifty-six elderly adults aged 65 years and older (elderly group) and 60 young adults in their 20-40 s (young group) with natural dentition participated in this study. The maximum occlusal force on the habitual chewing side was measured using dental prescale. Next, the amount of glucose extraction when subjects chewed a gummy jelly on their habitual chewing side for 20 s was measured. The maximum occlusal force and masticatory performance in the elderly and young groups were compared between males and females. The relationship between the maximum occlusal force and masticatory performance was also investigated. The maximum occlusal force in the elderly and young groups was larger in males than in females, and the difference was significant. The amount of glucose extraction in the elderly and young groups was higher in males than in females, and the difference was significant. Regarding the relationship between the maximum occlusal force and the amount of glucose extraction, there was a significant positive correlation. These results suggest that there are gender differences in the masticatory function of the elderly adults with completely natural dentition, and these differences need to be noted in the evaluation of masticatory function.

Oral hypofunction and malnutrition among community-dwelling older adults: Evidence from the Otassha study

OBJECTIVE

This study investigated the association between oral hypofunction and malnutrition among community-dwelling older adults.

BACKGROUND

Oral hypofunction, a 7-component phenotype of the clinical features of oral health, has been described in Japan. Data about its association with nutritional status are limited.

MATERIALS AND METHODS

This cross-sectional study enrolled 715 adults (mean age, 73.5 years; range, 65-91 years) from the Otassha Study. Oral hypofunction was defined as the presence of ≥3 of the following 7 components: poor oral hygiene; oral dryness; low occlusal force; low articulatory oral motor skill; low tongue pressure; low masticatory performance; and compromised swallowing function. The Mini Nutritional Assessment^® -Short Form (MNA^® -SF) was used to assess the nutritional status. Malnutrition was defined as having an MNA^® -SF score of seven or less. The association between oral hypofunction and nutritional status was evaluated using ordinal logistic regression analyses.

RESULTS

The prevalence rates of oral hypofunction and malnutrition were 42.7% and 4.1%, respectively. Multivariable Poisson regression analyses revealed that oral hypofunction was associated with malnutrition. The adjusted relative risk of malnutrition in the study participants with oral hypofunction was 3.00 with a 95% confidence interval of 1.29-6.98.

CONCLUSION

Community-dwelling older adults whose oral functions were compromised in multiple aspects had poor nutritional status.

The Significance of Posterior Occlusal Support of Teeth and Removable Prostheses in Oral Functions and Standing Motion

The purpose of this study was to evaluate the effect of posterior occlusal support of natural teeth and artificial teeth on oral functions and standing motion. Patients who had been treated with removable prostheses were enrolled as the subjects. Their systemic conditions (body mass index (BMI) and skeletal muscle mass index (SMI)) were recorded. The subjects were classified into two groups according to a modified Eichner index: B1-3 (with posterior occlusal support) and B4C (without posterior occlusal support). Maximum occlusal force (MOF), masticatory performance (MP), and standing motion (sway and strength) were evaluated for cases with and without removable prostheses. There were no significant differences in BMI and SMI between the B1-3 group and the B4C group. The subjects with removable prostheses demonstrated significantly higher values in MOF, MP, and sway and strength than the subjects without removable prostheses. The comparison of oral functions between the B1-3 group and the B4C group revealed that the positive effect of posterior occlusal support of natural teeth and removable prostheses and the significant positive effects of posterior occlusal support on standing motion were partly observed in these comparisons. Posterior occlusal support of natural teeth and even of removable prostheses may contribute to the enhancement of oral functions and standing motion.