Effects of denture use on occlusal force on abutment teeth in molar distal-extension edentulism.

PURPOSE: The present clinical study aimed to investigate the load exerted on abutment teeth in patients with distal extension edentulism, with and without a removable partial denture (RPD). METHODS: A total of 55 volunteers with distal extension edentulism who were fitted with an RPD participated in the present study. Occlusal force was measured by having the patients bite down on an occlusal force measuring sheet, and the occlusal forces on both the abutment teeth and the entire dentition with and without the RPD were compared using the Wilcoxon signed-rank test (P < 0.05). The occlusal forces on the abutment and non-abutment teeth were also compared. RESULTS: The median total occlusal force with the RPD in place was significantly greater than that without the RPD, while the median occlusal force on the abutment teeth without the RPD in place was significantly greater than that on the abutment teeth with the RPD. The occlusal forces on the abutment teeth were significantly greater than those on the non-abutment teeth. CONCLUSIONS: Within the limitations of the present study, we found that the occlusal forces were greater on the abutment than the non-abutment teeth, and that RPDs may reduce the occlusal forces on abutment teeth.

Clinical Measurements of Force Exerted on Anterior Teeth in Partial Edentulous Distal Extension.

PURPOSE: To determine the influence of partial edentulous distal extension and the use of removable partial dental prostheses in partially edentulous areas on the force exerted on the anterior teeth. MATERIALS AND METHODS: A total of 83 volunteer patients participated in this study. The occlusal force was measured using an occlusal force measuring sheet in the patient's mouth. The occlusal forces and ratios were compared using the Wilcoxon signed-rank test (P < .05). RESULTS: The force exerted on the anterior teeth increased significantly as the number of remaining teeth decreased in an edentulous distal extension. The force exerted on the anterior teeth decreased significantly with the use of a removable partial dental prosthesis. CONCLUSIONS: In a clinical setting, when the number of remaining teeth in a partial edentulous distal extension decreases, the burden on the anterior teeth increases. Our findings suggest that, for patients with partial edentulous distal extension, using a removable partial dental prosthesis is effective in preserving the residual anterior teeth by reducing excessive force.

Clinical measurement of force exerted on anterior teeth in partial edentulous distal extension.

PURPOSE: The aim of this clinical study was to determine the influence of partial edentulous distal extension and the use of removable partial dental prostheses in partially edentulous areas on the force exerted on the anterior teeth. MATERIALS AND METHODS: Eighty-three volunteer patients participated in this study. The occlusal force was measured by using an occlusal force measuring sheet in the patient's mouth. The occlusal forces and ratios were compared with the Wilcoxon signed-rank test (p < 0.05). RESULTS: The force exerted on the anterior teeth increased significantly as the number of remaining teeth decreased in an edentulous distal extension. The force exerted on the anterior teeth decreased significantly with the use of a removable partial dental prosthesis. CONCLUSION: When the number of remaining teeth decreases in a partial edentulous distal extension, the burden on the anterior teeth increases in a clinical setting. Our findings suggest that, for patients with partial edentulous distal extension, using a removable partial dental prosthesis is effective in preserving the residual anterior teeth by reducing excessive force. Int J Prosthodont 2023. doi: 10.11607/ijp.8281.

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

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

Features of Masticatory Behaviors in Older Adults with Oral Hypofunction: A Cross-Sectional Study.

Although many studies have shown the relationships between oral function and nutrition and health, few reports have investigated the masticatory behaviors of older people. This study aimed to clarify the relationships between oral function and the masticatory behaviors and features of masticatory behaviors with oral hypofunction. A total of 98 community-dwelling independent older adults participated. Seven oral conditions related to oral hypofunction were examined, and the masticatory behaviors when consuming a rice ball were measured. The participants were divided into two groups according to the criteria for oral hypofunction, and the masticatory behaviors were compared. Furthermore, the relationship between masticatory performance and the number of chews was investigated. The chewing rate of the oral hypofunction group was slower than that of the no oral hypofunction group, but there was no difference in the number of chews and chewing time. The decreased tongue-lip motor function group showed a slower chewing rate, and the decreased tongue pressure group showed a smaller number of chews and shorter chewing time. No significant correlation was observed between masticatory performance and behavior. In conclusion, older adults with oral hypofunction chewed slowly due to decreased dexterity, while, even if oral and masticatory function decreased, no compensatory increase in the number of chews was observed.

Oral Functions Are Associated with Muscle Strength and Physical Performance in Old-Old Japanese.

Grip strength and walking speed are considered to be important indicators of physical frailty. However, no study has contemporaneously examined any association of multiple oral functions with grip strength and walking speed. The purpose of this study was to examine which oral functions are associated with muscle strength (grip strength), physical performance (walking speed) or both. The study participants were 511 community-dwelling people (254 men and 257 women) aged 77-81 years old. Six oral functions-oral wetness, occlusal force, tongue-lip motor function, tongue pressure, masticatory performance and swallowing function-were measured. Grip strength and walking speed were also measured. A partial correlation analysis, adjusted for gender, showed that occlusal force, tongue-lip motor function, masticatory performance and swallowing function were significantly associated with both grip strength and walking speed. In addition, tongue pressure was significantly associated with grip strength. A general linear model showed that tongue pressure and occlusal force were significantly associated with grip strength. Swallowing function and tongue-lip motor function were significantly associated with walking speed. It is suggested that there are different oral function measures for muscle strength and physical performance, and these oral function measures could be a useful proxy for physical frailty.

Influence of mandibular distal extension implant-supported removable partial dentures on the force exerted on maxillary anterior teeth.

Purpose This study aimed to determine the influence of mandibular free-end partial edentulism and use of conventional or implant-supported removable dental prostheses in the partially edentulous area on the load exerted on the maxillary anterior teeth.Methods A jaw model with mandibular free-end missing teeth was used, and a distal extension, removable partial dental prosthesis was fabricated to replace the missing posterior teeth. Four experimental conditions were set up: 1) without prosthesis, 2) with a conventional removable partial dental prosthesis, 3) with an implant-supported removable partial dental prosthesis, and 4) with a complete dental arch. Strain gauges were attached to the root surface of the maxillary left central incisor, canine, first premolar, and first molar. The load exerted on them was calculated based on the calibration coefficient. An occlusal load of 49 N was applied, and the forces were compared using a Kruskal-Wallis test (P < 0.05). Results The load exerted on the maxillary anterior teeth increased significantly with no prosthesis, decreased significantly with a conventional removable partial dental prosthesis, and decreased even more significantly with an implant-supported removable partial dental prosthesis. Conclusions The burden on the maxillary anterior teeth decreased with the use of a removable partial dental prosthesis and decreased even further with the use of an implant-supported dental prosthesis. The use of an implant to support a distal extension removable partial dental prosthesis is potentially effective in preserving the remaining teeth and tissues by reducing excessive stress in patients with mandibular free-end partial edentulism.

Influence of mandibular free-end partial edentulism on the force exerted on maxillary anterior teeth.

PURPOSE: The purpose of this study was to determine the influence of mandibular free-end partial edentulism and the wearing of removable partial dentures in the partially edentulous area on the force exerted on maxillary anterior teeth. METHODS: A commercially available jaw model with exchangeable teeth was used. Seven experimental conditions of mandibular free-end edentulism were set up and a distal extension removable partial denture to replace missing posterior teeth was fabricated. Strain gauges were attached to the root surface of the maxillary left central incisor, canine, first premolar and first molar, and the force exerted on them was calculated based on the calibration coefficient. An occlusal load of 49 N was applied and the forces were compared with the Kruskal-Wallis test (P < 0.05). RESULTS: The force exerted on the maxillary anterior teeth increased significantly as the number of remaining teeth decreased. The force exerted on the maxillary anterior teeth decreased significantly with use of a removable partial denture. CONCLUSIONS: When the number of remaining teeth decreases in mandibular free-end partial edentulism, the burden on the maxillary anterior teeth increases. Our findings suggest that for patients with mandibular free-end partial edentulism, wearing a removable partial denture is effective in preserving the remaining teeth by reducing excessive stress.

Longitudinal changes in mouthguard fit: Reliability of an evaluation method.

BACKGROUND/AIM: A mouthguard should be replaced when it deteriorates or becomes deformed as a result of the softness or flexibility of the material. The question, however, is how long can one use a mouthguard and when should one replace it with a newly made mouthguard? The aim of this study was to develop an improved method for measuring the fit of mouthguards based on previous reports and to examine its reliability. MATERIAL AND METHODS: Silicone fit-testing material was applied to the inner surface of the mouthguards of 12 participants, and the mouthguards were inserted into the participants' oral cavity. After the test material had set, the mouthguard was weighed. The intra-rater reliability and inter-rater reliability were analyzed using intraclass correlation coefficients. RESULTS: The intra-rater reliability was 0.813 (P < .001), and the inter-rater reliability was 0.817 (P < .001). Both values were greater than 0.7, suggesting that this measuring method had sufficient reliability. CONCLUSIONS: The results of this study indicate that mouthguard fit can be evaluated longitudinally to determine the optimal time to replace a mouthguard.