Mandibular movements and bite force in Alzheimer's disease before and after new denture insertion

Systemic Factors Affecting Prognosis in Restorative and Prosthetic Dentistry: A Review

The field of restorative and prosthetic dentistry focuses on restoring lost tooth structures and replacing missing teeth and lost tissue to restore or improve esthetics and oral health. Many systemic factors such as metabolic, bone, autoimmune, cardiovascular, and endocrine disorders can affect healing procedures, and bone density and impact oral health. Hence patients suffering from systemic disease when treated for prosthodontic rehabilitation can have negative prognostic outcomes. The commonest prosthodontic treatments that can be affected include dental implants, fixed prostheses, and removable prostheses. Understanding and managing these systemic factors play a key role in the success of prosthodontic treatment.

Occlusion dysfunction and Alzheimer's disease: Mendelian randomization study

Aim

Occlusion dysfunction (OD) is increasingly linked to Alzheimer's disease (AD). This study aimed to elucidate the causal relationship between OD and AD using Mendelian randomization (MR) analysis.

Materials and methods

Genome-wide association study (GWAS) meta-analysis data obtained from FinnGen, IEU Open GWAS, and UK Biobank (UKBB) was represented as instrumental variables. We validated the causal relationship between periodontal disease (PD), loose teeth (PD & occlusion dysfunction), dentures restoration (occlusion recovery), and AD.

Results

According to the MR analysis, PD and AD have no direct causal relationship (P = 0.395, IVW). However, loose teeth significantly increased the risk of AD progression (P = 0.017, IVW, OR = 187.3567, 95%CI = 2.54E+00-1.38E+04). These findings were further supported by the negative causal relationship between dentures restoration and AD (P = 0.015, IVW, OR = 0.0234, 95%CI = 1.13E-03-0.485).

Conclusion

The occlusion dysfunction can ultimately induce Alzheimer's disease. Occlusion function was a potentially protective factor for maintaining neurological health.

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.

Single implant overdenture reinforced with a metallic framework: A 2-year clinical follow-up

INTRODUCTION

To prevent single-implant overdenture (SIO) fracture, the inclusion of a framework in the overdenture has been suggested. However, no investigations verified their benefits.

OBJECTIVE

To evaluate prosthetic maintenance events, patient satisfaction, and mastication of SIO reinforced by metallic framework users.

MATERIAL AND METHODS

Fifteen volunteers had a new set of complete dentures converted into an SIO containing a framework. Maintenance events were recorded, while patient satisfaction was assessed using a visual analog scale. Masticatory performance (MP) was evaluated using the sieving method, maximum bite force (MBF) by pressure sensors, and masseter thickness by ultrasound. Measurements were performed 2, 12, and 24 months after SIO use. Repeated-measures ANOVA and paired Student's t-tests (p < 0.05) were applied.

RESULTS

Matrix exchange was the most prevalent maintenance event (83.6%), and no SIO was fractured during the entire follow-up. Satisfaction with the SIO stability decreased (p < 0.01) after 12 months. MP did not change between evaluations (p > 0.05). Conversely, MBF and masseter thickness improved after 12 and 24 months of SIO use (p < 0.05).

CONCLUSIONS

Reinforced SIO did not fracture during 2 years but requires maintenance. It improves bite force and muscle thickness, maintaining MP values. Satisfaction with SIO stability decreased in the first year of use.

The Association between Age-Related Changes in Oral Neuromechanics and Alzheimer's Disease

The global population of 80 years and older is predicted to reach 437 million by 2050. As overall brain structure and function progressively degrades, older and younger adults show differences in sensorimotor performance and brain activity in the sensorimotor regions. Oral sensorimotor functions are an important area of focus in natural aging and Alzheimer’s Disease (AD) because oral health issues are commonly found in both elderly and AD populations. While human behavioral studies on changes in oral sensorimotor functions abound, very little is known about their neuronal correlates in normal and pathological aging.

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.

Evaluation of Satisfaction Perceived by Prosthetic Patients Compared to Clinical and Technical Variables

Objectives:

The purpose of this study is to relate the clinical quality of the complete denture and specific anamnestic factors to the level of satisfaction perceived by patients. Also identifying possible prognostic parameters that could be predictive of future satisfaction.

Materials and Methods:

On the basis of a substantial existing literature, the most appropriate parameters to determine the prosthetic quality have been determined to evaluate the satisfaction perceived by patients about their denture; a completely new questionnaire has been drawn up. Ninety-eight patients have been included in the research, they have undergone a clinical examination, and they have filled out the questionnaire anonymously. The ANOVA test and Pearson correlation test have been employed to relate clinical and anamnestic factors to the overall satisfaction score.

Results:

The average level of patients’ satisfaction was between “quite satisfied” and “very satisfied.” There is no significant variability of satisfaction related to the type of prosthesis. The ANOVA test did not verify relationships between the overall satisfaction score and the anamnestic data examined. Pearson linear correlation coefficient between the overall prosthetic quality and the general satisfaction perceived by patients is 0.493 (P < 0.01). Extension of the prosthetic body (r = 0.478; P < 0.01) and retention (r = 0305; P < 0.05) are in correlation with the overall patients’ satisfaction.

Conclusion:

there is a moderately strong relationship between the overall prosthetic quality and the general satisfaction perceived by patients. Particularly, the retention and the adequate extension of the prosthetic body appear to be factors that are most associated with satisfaction. Instead, the anamnestic factors are not related to overall satisfaction score.

Mastication and oral health-related quality of life in removable denture wearers with Alzheimer disease

STATEMENT OF PROBLEM

Alzheimer disease (AD) can affect masticatory function, affecting oral health-related quality of life (OHRQoL). Whether oral rehabilitation with conventional removable prostheses can restore masticatory function and improve OHRQoL in these individuals is unknown.

PURPOSE

The purpose of this clinical study was to evaluate the influence of oral rehabilitation with removable prostheses on masticatory efficiency and OHRQoL in elders with and without AD.

MATERIAL AND METHODS

Thirty-two elders with mild AD (n=16, mean age=76.7 ±6.3 years) or without AD (n=16, mean age=75.2 ±4.4 years) were recruited. All participants first underwent masticatory efficiency and OHRQoL evaluations, and 2 months after insertion of new removable prostheses, the variables were reassessed. Masticatory efficiency was determined using the sieving method, and OHRQoL was measured by applying the Geriatric Oral Health Assessment Index (GOHAI). The data from the baseline and after insertion of the new removable prostheses were compared by paired t test. Group differences at each time point were assessed by t test (α=.05).

RESULTS

After insertion of the new removable prostheses, masticatory efficiency and OHRQoL improved in both the elders with AD and the control. At baseline, elders with AD had lower masticatory efficiency and higher OHRQoL than controls (P<.05). After removable prosthesis insertion, elders with AD continued to show lower masticatory efficiency values than controls, but their OHRQoL was similar.

CONCLUSIONS

Oral rehabilitation with new removable prostheses improved the masticatory efficiency and OHRQoL of elders with and without AD, although masticatory efficiency did not reach control levels in elders with AD.

Association between chronic periodontitis and the risk of Alzheimer's disease: a retrospective, population-based, matched-cohort study

Background

Although recent short-term cross-sectional studies have revealed that chronic periodontitis (CP) may be a risk factor for increased cognitive impairment in patients with Alzheimer’s disease (AD), systematic reviews and long-term longitudinal studies have provided less clear evidence regarding the relationship between CP and AD. Therefore, we conducted a retrospective cohort study using the National Health Insurance Research Database (NHIRD) of Taiwan to determine whether patients with CP are at increased risk of developing AD.

Methods

We conducted a retrospective matched-cohort study using the NHIRD of Taiwan. We identified 9291 patients newly diagnosed with CP between 1997 and 2004. A total of 18,672 patients without CP were matched to the patient cohort according to sex, age, index year, co-morbidity and urbanisation level. Cox proportional hazards regression analyses were performed to evaluate the subsequent risk of AD.

Results

Patients with CP had a higher prevalence of hyperlipidaemia, depression, traumatic brain injury and co-morbidities, as well as higher urbanisation levels, than those in the unexposed cohort (all p < 0.01). At the final follow-up, totals of 115 (1.24%) and 208 (1.11%) individuals in the CP exposed and unexposed groups, respectively, had developed AD. Patients with 10 years of CP exposure exhibited a higher risk of developing AD than unexposed groups (adjusted HR 1.707, 95% CI 1.152–2.528, p = 0.0077).

Conclusions

Our findings demonstrate that 10-year CP exposure was associated with a 1.707-fold increase in the risk of developing AD. These findings highlight the need to prevent progression of periodontal disease and promote healthcare service at the national level.