This study investigated changes in chewing satisfaction from old to new dentures, exploring how perceived masticatory difficulty with the old denture influenced food intake with the new dentures. Additionally, factors influencing overall masticatory satisfaction with the new dentures were examined. Consecutive sampling involved edentulous individuals seeking replacements for both maxillary and mandibular complete dentures. A total of 103 edentulous individuals(49 males, 54 females; age range: 39-87 years; mean age: 71.6±8.6 years)participated. At the baseline visit, patients provided general satisfaction ratings for their dentures in terms of subjective mastication. A 12- item questionnaire, using a 100mm visual analog scale(VAS), assessed their ability to chew specific foods(tofu, fish cake, bean sprouts, cubic rice crackers, rice crackers, and squid jerky)with existing maxillary and mandibular dentures. The study revealed a significant increase in VAS for overall masticatory satisfaction and the intake of six Japanese foods with diverse textures. Notably, perceived masticatory difficulty with previous dentures exerted a substantial impact on subsequent food intake with new dentures. Factors influencing perceived mastication with the new dentures included crunchy foods(cubic rice crackers and rice crackers)and elastic foods(fish cake). These findings highlight the considerable influence of old denture-related masticatory difficulty on overall masticatory satisfaction and subsequent food intake with new dentures. The study suggests valuable insights for treatment planning and denture design, emphasizing the necessity of considering these factors when fabricating new dentures and providing guidance to patients post-insertion.

Age-related hearing loss (ARHL) and impaired gait both independently heighten the risk of accidental falls among older adults. However, the combined impact of these factors remains unclear. We analyzed the data of 786 community-dwelling Japanese older adults. Hearing was evaluated at frequencies of 1.0 and 4.0 kHz, with participants categorized into ARHL (> 25 dB) and non-ARHL groups. Gait was also assessed, defining slow gait (SG) as speeds one standard deviation below the age- and sex-specific mean. Participants were divided into four groups based on their ARHL and SG statuses and were monitored annually for 8 years to track falls and related injuries. Throughout the follow-up, incidents included 328 single falls (9.6/100 person-years), 117 multiple falls (2.8/100 person-years), 249 minor injuries from falls (6.7/100 person-years), and 55 fractures due to falls (1.3/100 person-years). Cox proportional hazard regression models showed that participants without ARHL but with SG faced a significantly increased risk of frequent falls. Furthermore, ARHL combined with SG significantly raised the risk of both single and frequent falls, and increased the incidence of both minor and severe fall-related injuries, including fractures. In contrast, no significant association was found between ARHL alone and fall-related incidents. These findings suggest that the previously reported risk associated with hearing loss in fall incidents predominantly relates to gait impairment. The co-occurrence of ARHL and SG significantly escalates the risk of falls and related injuries, highlighting the critical need for routine gait monitoring.

This study examined changes in masticatory function indices, maximum occlusal force, masticatory performance, and masticatory score before and after removable prosthesis treatment, taking into account the prosthetic difficulty level, which assesses factors such as the shape of the residual ridge and properties of the mucous membrane. Participants(n=40, mean age 75.0±6.8 years)seeking prosthetic treatment were evaluated. Significant improvements in maximum occlusal force were observed in Classifications I and III, while masticatory performance improved significantly in Classification III. Multiple regression analysis indicated that post-treatment maximum occlusal force was significantly influenced by pre-treatment maximum occlusal force(p = 0.01), with marginal significance in the number of remaining teeth(p = 0.06)(adjusted R2 = 0.38). Factors significantly associated with post-treatment masticatory performance included pre-treatment masticatory performance(p = 0.03)(adjusted R2 = 0.27). Additionally, the post-treatment masticatory score was significantly associated with the pre-treatment masticatory score(p < 0.00)(adjusted R2 = 0.55). The findings suggest challenges in improving masticatory indices, particularly at Level IV, the most difficult index. Post-treatment maximum occlusal force, masticatory performance, and masticatory score significantly correlate with the pre-treatment status of each index. These results propose the utility of prosthetic difficulty level and masticatory indice(msasticatory performance, maximum occlusal force, and masticatory score)as predictive indicators for patients seeking denture treatment.

Data on estimating the vertical dimension of occlusion（VDO）for fabricating a complete denture based on tongue pressure, which is related to masticatory and swallowing functions, are scarce. This study aimed to examine the changes in tongue pressure on raising or lowering of the VDO from the most comfortable position（MCP）. Ten edentulous, including Eichner C3, patients with existing dentures（six men and four women; mean age, 78.6±7.14 years）were recruited from a hospital setting. Twelve different height-positioning stimulus stainless-steel blocks were used（from +1 mm to 6 mm and +9 mm and from -1 mm to -4 mm）. VDO from the most comfortable position （MCP）and the tongue pressure at the respective height were measured. One-way analysis of variance（ANOVA）and Dunnett’s test were performed to analyze the differences in tongue pressure at different VDOs. There were no significant differences between the stimulus intervals（-1 to -4 mm, p = 0.99）on lowering VDO from MCP. Tongue pressure decreased marginally when the VDO was raised +5 mm from the MCP（p=0.054）; it continued to show a significant decrease at +6 mm（p=0.041）and +7 mm（p=0.035）from MCP. Tongue pressure did not change significantly when VDO was lowered and raised to +5 mm from MCP. These results suggest that VDO may be set to 5 mm from MCP when fabricating new complete dentures.

The vertical dimension of occlusion（VDO）must be correctly estimated when fabricating complete dentures to achieve efficient mastication and swallowing. The comfortable zone（CZ）method for VDO estimation is based on trichotomous subjective response. However, the difference in comfort level within and out of the CZ still needs to be determined. Therefore, this study aimed to examine the differences in subjective comfort on a 100-mm visual analog scale（VAS）when raising or lowering the VDO and to assess the relationship among the responses to the CZ method. Eight edentulous patients（five men and three women, with a mean age of 78.5±7.6 years）were recruited. The VAS score was obtained two times at the most comfortable position（MCP）and when it was raised from +1 to +7 mm（7VDO）. The VAS score was also obtained when the MCP was lowered from -1 to -3 mm（3VDO）. One-way analysis of variance and Bonferroni’s multiple comparison test were performed to analyze the differences in VAS scores at 11 VDOs. The VAS score significantly decreased when the VDO was raised by +3 mm from the MCP（p = 0.009）and continued to decrease in +4（p = 0.001）, +5, +6, and +7 mm（p < 0.001, respectively）. In addition, it significantly decreased when the VDO was lowered by -2 mm from the MCP（p = 0.048）. The results suggest that VDO estimates may be appropriate between -1 and +2 mm from the MCP when fabricating new complete dentures.

Statement of problem. Limited data, especially in vivo data, exist regarding translucency parameter (TP) values for vital anterior nonrestored dentition. Additionally, published information on the CIELab values of vital enamel at a theoretical infinite thickness is lacking. Obtaining TP and CIELab values in a population that varies in terms of ethnicity, age, and sex would be useful to inform the development and placement of esthetic dental restorations that more accurately capture the complex optical qualities of enamel. Purpose. The purpose of this clinical study was to investigate in vivo the TP and CIELab values of vital anterior incisor enamel at a theoretical infinite thickness in a diverse pool of participants who varied in age, ethnicity, and sex. Material and methods. Spectral reflectance measurements (380 to 780 nm at 2-nm intervals) of the mid-incisal region of vital, unrestored maxillary anterior teeth were made in 120 participants, equally divided into 2 sexes, 4 racial or ethnic groups, and 5 age ranges. Instruments were oriented to achieve 0-degree observation and 45-degree illumination, and spectral measurements were made with white and black silicone backgrounds. Reflectance spectra of the incisal enamel from both the black and white silicone backing were used to fit to the Kubelka-Munk (K-M) reflectance theory. The CIEDE2000 color difference formula was used to determine TP, and data were compared among participant demographics. CIELab color coordinate values for enamel at an infinite thickness were calculated by using a D65 illumination and CIE standard human (2-degree) observer. To determine value ranges and significant differences among participant groups, CIELab values were analyzed with a 4-way ANOVA, and TP values were analyzed with a generalized linear mixed model. Pairwise comparisons of interest were evaluated with Bonferroni-corrected Student t tests. Results. For maxillary central incisor enamel, the average TP was 10.1 +/- 3.6, and the average CIELab color coordinates were L*=73.5 +/- 7.6, a*=2.2 +/- 1.8, b*=11.9 +/- 8.4. TP values of incisal enamel significantly differed among specific age and ethnic groups, with general significant interactions of age and sex (P=.009), as well as ethnicity and age (P=.042). CIE color coordinates of enamel at an infinite thickness were found in the L* coordinate among different age groups with the same sex and ethnicity, specifically when comparing CIELab direction with the population characteristics of age (P=.011) and the interaction between age, sex, and ethnicity (P=.035). Conclusions. In vivo L* values and TP values of incisal enamel differed significantly among groups determined by ethnicity, age, and sex. (J Prosthet Dent 2023;130:878-84)

The aim of this study was to clarify the relationship between treatment difficulty based on the morphological evaluation of the Japanese Society of Prosthodontics and the status of frailty and oral hypofunction (OHF) in patients requiring prosthodontic treatment due to missing teeth.Older adults aged 65 years and over who visited a dental clinic in Japan and required prosthetic dental treatment by removable dentures due to tooth defects and were in cooperation with this research were included in the study.OHF (including seven items: oral hygiene, oral dryness, occlusal force, tonguelip motor function, tongue pressure, masticatory function, and swallowing function) , oral status (including treatment hardness classification advocated by the Japanese Society of Prosthodontics) , and frailty were evaluated.Among the patients who visited the community dental clinic requiring prosthodontic treatment, 71 (87.7%) were classified as having OHF.In the multivariate analysis, subjective masticatory function was a significant factor in treatment difficulty and frailty.In conclusion, in elderly patients who required treatment for missing teeth, many were diagnosed with OHF.Furthermore, subjective masticatory function was associated with both treatment difficulty and frailty.Keywords： oral hypofunction, frailty, treatment hardness classification

BACKGROUND:Although inconsistency between objective and subjective hearing loss among older adults has been suggested, a systematic examination of the cognitive and physical functioning among such older adults is lacking. Our objective was to assess the cognitive, physical, and mental profiles associated with the discrepancy. METHODS:The auditory acuity of 696 community-dwelling older adults was evaluated using a pure-tone average of hearing thresholds at 1.0 and 4.0 kHz in the better-hearing ear. Participants were then stratified as follows: normal hearing ≤ 25 dB, mild loss >25 dB and ≤40 dB, and moderate loss >40 dB and ≤70 dB. Global cognition, gait speed, and depressive symptoms were also assessed. RESULTS:Among older adults, 63.5% of those with mild hearing loss and 22.2% of those with moderate hearing loss did not recognize hearing difficulties. Significantly lower cognition and gait performance were observed in those with moderate hearing loss without subjective hearing loss (i.e., overestimation of hearing acuity) than in those with subjective hearing loss. Furthermore, older adults with subjective hearing loss showed a higher tendency toward depression than those without subjective hearing loss, irrespective of objective hearing loss. CONCLUSIONS:Our results suggest that failure to recognize a high level of age-related hearing loss may be related to impaired cognition and gait performance among older adults. Subjective hearing loss may indicate a tendency toward depression.

The aim of the study was to ascertain the relationship between Oral Health -Related Quality of Life (OHRQoL) and various oral functions in patients who visited a dental clinic and needed prosthetic dentistry.Patients aged 65 years or older who visited a

Background/purpose: Dentures are important for the reconstruction of occlusal support and masticatory performance for older adults with poor dentition. We aimed to elucidate the oral health factors associated with malnutrition in older adults requiring long-term care, including denture use. Materials and methods: This cross-sectional study included 322 older adults (63 men, 259 women; mean age, 86.6 +/- 6.9 years) who required long-term care in rural Japan. The participant's nutritional status was assessed using the Mini Nutritional Assessment-Short Form (MNAO-SF). Oral health was assessed using participant's dentition and oral function. Barthel Index (BI) and medical history were measured for assessing general health status. Multiple logistic regression analyses were performed to determine the oral health factors associated with malnutrition. Results: The proportion of participants with malnutrition was 17.2%. The BI score (odds ratio [OR], 0.95; 95% confidence interval [CI] 0.93-0.98, p<0.001), having <20 teeth and dentures (OR 0.42; 95%CI 0.18-0.99; p = 0.047), and poor lip-closure ability (OR 2.86; 95%CI 1.32-6.20; p = 0.008) were significantly associated with malnutrition. Conclusion: Denture use, lip-closure ability, and activities of daily living were significantly associated with malnutrition in older adults requiring long-term care, suggesting that wearing dentures for tooth loss and maintaining oral function contributes to nutritional status. (c) 2021 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).

A nylon partial removable dental prosthesis (PRDP) is aesthetically superior to a traditional PRDP. However, the nylon surface becomes rough after long-term use.

BACKGROUND:Several methods exist for objectively evaluating chewing efficiency by using gummy jelly. However, the validity of the subjective visual evaluation of chewing efficiency has not been assessed.OBJECTIVE:To verify with an epidemiological study, the validity of a visual scoring method using gummy jelly by testing the relationship between masticatory performance (MP) using a fully automatic measuring system and visual score (VS) using a visual scoring method.METHODS:Community-dwelling elderly individuals (n = 1234) ≥70 years old participated. One evaluator measured VS consecutively after participants chewed the gummy jelly (ie, actual-VS). The chewed jelly was photographed. Two evaluators used the photograph to measure the gummy jelly (ie, photo-VS). To test the validity of both methods, the correlation between actual-VS and MP and between photo-VS and MP were analysed. Inter-rater reliability between the evaluators of photo-VS was analysed.RESULTS:Significant correlations existed between actual-VS and MP and between photo-VS and MP (r = 0.86-0.87; P < 0.001). The intra-class correlation coefficient of the inter-rater reliability for photo-VS was very high (0.93; P < 0.001; 95% confidence interval: 0.877-0.953); however, the distribution of photo-VS deviated slightly from the actual-VS. A large coefficient of variation in the MP for low VSs suggested the influence of incomplete comminution, which was not reflected by the VS, and the accidental swallowing of small pieces during chewing.CONCLUSION:The VS deviated slightly from the MP calculated using a fully automated method; however, the VS can be utilised for epidemiological surveys with numerous participants.

The relation between occlusal force and general motor ability induced by lower-limb musculature is unclear. To identify indicators of oral and lower-limb muscle weakness, this study examined the relation between masticatory muscle strength and lower limb muscle force in 742 community-dwelling elderly adults (315 men and 427 women, mean age 73.3 ± 5.5 years) living in Itabashi ward, Tokyo. Multiple regression analysis of the relation between occlusal force and knee extension torque, in relation to age and sex, showed a significant correlation between the two variables (r = 0.348, P < 0.001), which indicates that occlusal force is a determinant of knee extension torque. Occlusal force remained significantly correlated with knee extension torque after adjustment for factors known to be related to the latter. In conclusion, chewing function and lower-limb motor function were significantly correlated and thus might be indicators of muscle weakness in elderly adults.

Purpose: Tongue movement with unstable swallowing cause artifacts on magnetic resonance imaging (MRI). This may be associated with loss of occlusal support. This study aimed to clarify whether motion artifacts can be mitigated by denture wearing during MRI examination in patients without occlusal support, and whether denture wearing affect tongue stability, form, and position were also evaluated. Methods: Ten subjects without occlusal support (6 male, 4 female; mean age 73.20 +/- 10.12 years) participated in the study. MRI was performed with dentures worn (DW), followed with removal of dentures (NDW). Luminance standard deviation (LSD) was measured in regions of interest in the axial and sagittal planes. The position of the base of the tongue (TB), tip of the tongue apex (TA), and tongue's long diameter (TLD) were compared between DW and NDW. Results: NDW evoked ambiguous MR images in the axial and sagittal planes compared with DW. There were significant differences in LSD between DW and NDW in both the axial (p = 0.047) and sagittal planes (p = 0.02). No significant difference in the position of TB were observed (p = 0.78). The position of TA was significantly more protruded with DW (p = 0.007). Also, TLD was significantly longer with DW (p = 0.001). Conclusions: Results of this study suggest that wearing the dentures during MRI examination reduces motion artifacts in edentulous patients without occlusal support, and maintained the normal form of the tongue during imaging. (C) 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Clear magnetic resonance imaging (MRI) is required to diagnose tongue cancer. However, the absence of occlusal support may cause tongue movements which are known to introduce artifacts on the MR image. This pilot study compared the manifest of artifacts from the tongue at rest and during motion using luminance standard deviation (LSD) to quantify the artifacts, in dentulous subjects. Participants were ten dentulous participants (5 males, 5 females; age 31.50 ± 8.38 years) with occlusal support. MRI was conducted with the tongue at rest and during lateral movement. The LSD was measured in the regions of interest (ROI) in the axial and sagittal planes. Tongue movement evoked unclear MR images, compared with the images taken at rest. Statistical analysis revealed that the LSD significantly differed between the tongue at rest and in motion in the axial (P = 0.004) and sagittal planes (ROI-A: P = 0.002, ROI-P: P = 0.006). These findings suggest that tongue movement introduces motion artifact and the LSD responds quantitatively to the magnitude of artifacts. Future studies will evaluate whether a prosthetic device used to provide occlusive support can decrease these artifacts when analyzed using LSD.