Effect of denture treatment on masticatory movement in patients with complete dentures

Factors Related to Masticatory Rhythm in Patients with Oral Tumors

Background: Older adults who have undergone surgery for oral tumors are at increased risk of impaired masticatory rhythm. This study investigated the correlations between masticatory rhythm, objective masticatory performance, and subjective masticatory performance as well as factors related to masticatory rhythm. Methods: The participants were 44 adults (24 men, 20 women; age range 42~90 years old) who had undergone maxillectomy, mandibulectomy, or glossectomy and were rehabilitated with a maxillofacial prosthesis. The number of functional contact teeth pairs was confirmed by intraoral examination. Chewing rate, cycle duration, coefficient of variation (CV) for cycle duration (reflecting the stability of masticatory rhythm), and mixing ability were measured simultaneously using a mastication movement rhythm tracking device during gum chewing. Maximum occlusal force was measured using the dental prescale system. Patients' perception of chewing ability was rated using a questionnaire. Results: The Spearman's rank correlation test revealed that mixing ability, patient-rated masticatory scores, cycle duration, CV for cycle duration, and maximum occlusal force showed significant correlations with chewing rate. Multiple linear regression analysis identified mixing ability and the CV for cycle duration as significant predictors of masticatory rhythm. Conclusions: Factors associated with a faster chewing rate were higher mixing ability and masticatory scores, greater maximum occlusal force, shorter cycle duration, and smaller CV for cycle duration. Stable masticatory rhythm and mixing ability are significant predictors of chewing rate. Poor masticatory performance and unstable masticatory rhythm can result in slower chewing and thus a higher risk of inadequate dietary intake.

Evaluation of masticatory performance by motion capture analysis of jaw movement

BACKGROUND

The assessment of masticatory performance (MP) is conducted in hospitals, but is difficult to perform in nursing facilities that lack specialists in dysphagia. To select the appropriate food textures in nursing practice, a simple method of evaluating the MP should be developed.

OBJECTIVE

The purpose of this study was to investigate motion parameters that influence MP by motion capture analysis of maxillofacial movement on chewing gummy jelly in healthy adults.

METHODS

The subjects were 50 healthy adults. The state of chewing gummy jelly was photographed using a high-speed camera. Simultaneously, we evaluated the amount of glucose extracted (AGE) obtained with gummy jelly as a reference value for MP. The subjects were divided into two groups: normal and low masticatory groups (NG and LG, respectively) based on the AGE. The cycle of mastication was classified into three phases: closing phase (CP), transition phase (TP) and opening phase (OP) through motion capture analysis of the video photographed. Parameters of jaw movement and their associations with the AGE were examined.

RESULTS

The transition phase rate (TR) and opening phase rate (OR) were correlated with the AGE. Furthermore, the TR in the NG was significantly higher than in the LG, whereas the OR was significantly lower than in the LG. The age, TR and opening velocity were significant independent variables.

CONCLUSION

Motion capture technology facilitated the analysis of jaw movement. The results suggested that MP can be evaluated by analysing the TP and OP rates.

Comparison of Masticatory Efficiency and Patient Satisfaction of Injection-Molded Conventional Complete Dentures and Biofunctional Prosthetic System Dentures: A Parallel Randomized Clinical Trial

Introduction Complete loss of natural teeth severely compromises the masticatory efficiency of geriatric patients and directly affects their general health. Biofunctional prosthetic system (BPS) has been developed as an alternate method of denture fabrication to match the higher expectations of patients. Studies comparing BPS dentures with injection-molded conventional complete dentures (IM-CCD) are lacking. Our study aimed to compare the masticatory efficiency and patient satisfaction of BPS dentures with IM-CCD. Methods This trial was designed as a randomized, prospective, single-center, double-blinded study with two parallel arms (BPS group and IM-CCD group) having an equal allocation (1:1). Completely edentulous patients aged 45-80 who visited our outpatient department between January and August 2018 were screened and enrolled according to our inclusion and exclusion criteria. Random sequence generation was done using an online randomization program. Allocation concealment was done using sequentially labeled opaque envelopes. The participants and the outcome assessors were blinded. A single operator performed all the clinical procedures in both groups under the guidance of the instructor. The age and gender of the patients were recorded for demographic data at baseline. Primary outcomes were assessed six weeks after denture insertion. The number of denture adjustments required during the first six weeks after denture delivery was recorded as the secondary outcome. Masticatory efficiency was evaluated by the volumetric single-sieve method. An abbreviated version of the Oral Health Impact Profile questionnaire for edentulous patients (OHIP-EDENT) was used for patient satisfaction scores. The total OHIP-EDENT score was calculated by adding all the responses to the 19 questions (ranging from 0 to 38). Individual domain scores were calculated by adding the response to all the questions in that domain. All the data obtained were tested for normality using the Kolmogorov-Smirnov test. Data were analyzed using either unpaired Student's T-test or Mann-Whitney U test for normal and non-normal data, respectively. The gender characteristics of the sample were compared using Chi-Square test. Results Two patients in the IM-CCD group and one patient in the BPS group were lost to follow-up. Hence only the secondary outcome data were analyzed for these patients. Primary outcome data of patients who were lost to follow-up were excluded from the analysis. No significant differences (p>0.05) were found between the two groups for age and gender characteristics of the samples. Masticatory efficiency for both peanut and carrot was found to be significantly higher (p<0.05) in the BPS group than in the IM-CCD group. No significant differences (p>0.05) in the mean scores were observed between the two groups for total OHIP-EDENT scores or the individual domain scores. No significant differences (p>0.05) were observed between the groups for the number of denture adjustments done. Conclusion Within the limitations of the trial, it can be concluded that the BPS dentures significantly improved the masticatory efficiency for both hard (carrots) and soft (peanuts) foods compared to the IM-CCD. However, there was no difference between the masticatory-related complaints domain scores between the two dentures. No significant differences were found between BPS dentures and IM-CCD with respect to overall patient satisfaction scores or post-insertion denture adjustments.

Path pattern and movement during mastication on habitual and non-habitual chewing sides

PURPOSE

To clarify the presence or absence of differences in path pattern and movement during mastication between the habitual and non-habitual chewing sides.

METHODS

Participants were 225 healthy adults with natural dentition. Mandibular movement while chewing gummy jelly on each side was recorded, and masticatory path pattern was classified into five types (one normal and four abnormal). The frequency of each pattern was measured and compared between chewing sides. The amount, rhythm, velocity, and stability of movement and masticatory performance were measured and compared between chewing sides.

RESULTS

A normal pattern was observed on the habitual chewing side in 84.4% of participants. There was a significant difference between chewing sides in masticatory path pattern (χ² = 35.971, P < 0.001). Values of parameters regarding the amount and velocity of movement and masticatory performance were significantly higher on the habitual chewing side. Values of parameters regarding rhythm and stability of movement were significantly lower on the habitual chewing side.

CONCLUSION

The present findings of functional differences between chewing sides in terms of path pattern and movement during mastication suggest that these factors should be analyzed on the habitual chewing side.

Masticatory path pattern and masticatory performance while chewing gummy jelly

The purpose of this study was to clarify masticatory path pattern and masticatory performance during gummy jelly chewing. A total of 235 healthy adults were asked to chew gummy jelly for 20 s on each side, and the masticatory movement was recorded using a Motion Visi-Trainer (MVT V1). Next, the amount of glucose extraction was measured as a parameter of masticatory performance. The masticatory path was classified into one of five patterns newly devised: normal pattern (N, opening: straight or concave, closing: convex) and abnormal patterns (A1-A4). The number of occurrences of each pattern was investigated and compared by sex and path pattern. Next, masticatory performance was compared between the normal pattern and the abnormal patterns by sex. Pattern N was the most frequently expressed in 346 cases out of 470 cases (73.6%), followed by patterns A1, A4, A2, and A3 in that order. Regarding the number of patterns observed, pattern N was the most common in both sexes, followed by pattern A1, with no significant difference between sexes. The amount of glucose extraction in each pattern was the highest in pattern N for both sexes, followed by A2 and others in that order, and a significant difference was observed between the normal pattern and the abnormal patterns. From these results, the existence of sex difference in masticatory path patterns during gummy jelly chewing was not proven, and that masticatory performance was higher with normal patterns than with abnormal patterns.

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.

Association between masticatory movement and oral and physical function in healthy older women

PURPOSE

This study examined the association between masticatory movement and oral and physical function in healthy older women using clinical assessments considering central motor control.

METHODS

A total of 107 independent older women (mean age, 74.37 ± 4.46 years; age range, 66-84 years) living in the community participated in this cross-sectional study. The subjects selected were those aged 65 years or older with at least 28 teeth and without oral dysfunction, temporomandibular joint (TMJ) disease, cerebrovascular disease, or neuromuscular disease. The following items of oral and physical function were measured: masticatory path pattern, masticatory perfor-mance, oral diadochokinesis (ODK), tongue pressure, single-leg stance with eyes open (SLS), stepping test, and grip strength. Logistic regression analysis adjusting for age was performed to investigate the association between masticatory movement and other items.

RESULTS

In total, 30.8% of subjects were classified into the abnormal group regarding masticatory path pattern, having a significantly lower value than that of the normal group in masticatory performance (unadjusted p = 0.021). After adjusting for age, the masticatory path pattern was significantly associated with masticatory performance ( p = 0.032); ODK /pa/ ( p < 0.001), /ta/ ( p = 0.022), and /ka/ ( p = 0.016); and stepping test ( p = 0.018). Tongue pressure, SLS, and grip strength were not significantly associated with masticatory path pattern.

CONCLUSION

Masticatory movement in older women was associated with masticatory performance, tongue and lip motor skills, and physical agility, which might be influenced by central motor control.

Masticatory movements and food textures in older patients with eating difficulties

Objectives

To investigate whether masticatory movements in older patients with eating difficulties were associated with oral motor function, physical function, and appropriate food textures.

Background

There are few reports on the association between masticatory movements and food textures in older patients with eating difficulties.

Materials and Methods

This cross‐sectional study involved outpatients at a clinic that specialised in eating and swallowing rehabilitation. Masticatory movements were evaluated as normal or abnormal masticatory path patterns. Oral and physical functions were assessed in terms of oral and physical status, muscle strength and motor skills. The appropriate food texture was determined based on fibreoptic endoscopic evaluation of swallowing and a video fluoroscopic swallowing study. The associations between food texture and masticatory organ, muscle strength and motor skills were analysed.

Results

A total of 126 outpatients (75 men and 51 women; mean age, 78.2 years; SD, 9.6 years) were included in the analysis. 68 participants (54.0%) showed abnormal masticatory movements. Masticatory movement was associated with masticatory performance (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.98‐0.99), oral diadochokinesis (OR = 0.55, CI = 0.35‐0.86) and stepping test (OR = 0.92, CI = 0.86‐0.97). Masticatory movement (OR = 2.94, CI = 1.23‐7.01) and the number of natural teeth (OR = 0.94, CI = 0.89‐0.99) were associated with normal food.

Conclusion

Masticatory movements in older patients with eating difficulties may be associated with appropriate food textures whilst being influenced by individual differences in systemic motor control. Masticatory movements may be as important as teeth to enjoy eating.

Stability of masticatory movements after placement of implant-supported denture

The purpose of this study was to clarify the stability of masticatory movement after placement of implant-supported denture. Fourteen patients (patient group) with mandibular implants denture and maxillary complete denture and 30 dentate adults (control group) were asked to chew a boiled fishpaste, and the masticatory movement was recorded using MKG. For the 10 cycles beginning with the 5th cycle of mastication, the parameters representing the stability of masticatory movement were calculated. Data collected at 1, 3, 6, 9 months and 1, 2, 3 years after insertion of implants denture were compared between sessions and also between the patient and control groups. The mean and standard deviation of the values in the patient group at 1 month after insertion of implants denture were large, but gradually decreased 6 to 9 months after insertion of implants denture. Each parameter maintained almost the same value from 1 to 3 years. The parameter values of the patient group were significantly larger than those of control group from 1 to 9 months after insertion of implants denture, but 1 year after insertion of implants denture, there was no significant difference between the two groups in 5 out of 7 parameters. From these results, it was suggested that a certain duration, about 9 months to 1 year, was necessary for patients with implants denture to adapt to the new masticatory function and that the timing of functional evaluation should be set to 1 year after insertion of implants denture.

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.

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.

Masticatory rhythm 3 months after treatment with unilateral implant-supported fixed partial prosthesis: A clinical study

STATEMENT OF PROBLEM

Whether treatment with an implant-supported fixed partial prosthesis (ISFPP) affects the masticatory rhythm in patients with unilateral posterior missing teeth is unclear.

PURPOSE

The purpose of this prospective clinical study was to determine the change in masticatory rhythm in participants with unilateral posterior missing teeth 3 months after treatment with an ISFPP and to assess whether treatment influenced the stability of the masticatory rhythm.

MATERIAL AND METHODS

Thirty participants (mean age 59 years; 17 women) with unilateral posterior missing teeth were treated with 1-, 2-, or 3-unit ISFPPs. Ten healthy individuals (mean age 36 years; 8 women) with a complete natural dentition were included in a control group. In this prospective study, each participant performed 3 masticatory assays (freestyle, unilateral right, and unilateral left) at baseline and at the 3-month follow-up. Each assay comprised 5 trials of 20 cycles masticating pieces of silicone placed in a latex bag. The time needed to complete the 20 masticatory cycles per trial was measured, and the mean masticatory frequency was calculated for each assay. Coefficients of variation were then calculated from the 5 mean values of the masticatory trials. Differences in the data at 3 months and baseline were analyzed by using the Wilcoxon or paired t tests. The control and treated groups were compared by analysis of variance or Mann-Whitney U tests (α=.05).

RESULTS

After 3 months, participants treated with ISFPPs showed an increase of 8.7% in masticatory frequency during freestyle mastication (P<.001) and an 8.0% increase during unilateral mastication on the treated side (P<.01). At baseline, the coefficient of variation of masticatory frequency on the treated side was higher in the ISFPP group than in the control group during unilateral mastication (P=.033). Three months after treatment, there was a significant reduction in the coefficient of variation during unilateral mastication on the treated side of the ISFPP group (P<.001). The treatment group also reached a masticatory frequency similar to that of the control group (75 and 78 cycles per minute, respectively).

CONCLUSIONS

Treatment with ISFPPs accelerated the masticatory rhythm of individuals with unilateral posterior missing teeth, who achieve similar rhythms to those with complete natural dentitions. The stability of the masticatory rhythm was also restored, indicating an improvement in masticatory function.

Chewing ability and oral health-related quality of life in frail elders after new complete dentures insertion: A paired controlled clinical trial

AIMS

To compare the effect of new complete dentures (CDs) on self-perceived masticatory ability (MA) and oral health-related quality of life (OHRQoL) in frail and nonfrail elders.

METHODS AND RESULTS

Twenty completely edentulous elders were assigned to two groups: frail and nonfrail (n = 10/each). MA was evaluated using a visual analogue scale. OHRQoL was assessed with the Oral Health Impact Profile (OHIP-Edent). Variables were evaluated with volunteers wearing their old and unsatisfactory CDs. Then, a new set of CDs was manufactured and all outcomes were reassessed 2 months after the insertion. Data were analyzed by repeated measures' analyses of variance and Tukey tests. MA for lettuce and peanuts was improved (P < .05) for the frail group after new CD insertion. Psychological discomfort and handicap OHIP-Edent domain improved (P < .05) for both groups after prosthetic treatment. Before treatment, controls reported greater psychological discomfort than the frail group. Meanwhile, the handicap domain score of frail patients improved to a level similar to that of the nonfrail group after treatment. Regardless of frailty, elders showed better MA scores for most food types after treatment and decreased OHIP-Edent domain values.

CONCLUSION

Self-reported MA and OHRQoL of frail elderly people were greatly improved after new CD use.