A Cluster Analysis of Oral and Cognitive Health Indicators: An Exploratory Study on Cholinergic Activity as the Link

INTRODUCTION

Poor oral health has been suggested as a risk factor for cognitive decline. Yet, biologically plausible mechanisms explaining this relationship remain unknown.

OBJECTIVES

We aimed (1) to identify oral and cognitive health clustering patterns among middle-aged to elderly Canadians and (2) to investigate the extent to which these patterns could be explained by bone mineral density (BMD), a proxy measure of the cholinergic neurons' activity.

METHODS

This cross-sectional study used baseline data from the Comprehensive cohort of the Canadian Longitudinal Study of Aging (CLSA). Oral health was assessed by a self-report questionnaire, and 7 task-based instruments measured cognitive health. We identified oral and cognitive health clusters, our outcome variables, using latent class analysis. Two sets of multivariate logistic regression and 95% confidence intervals were used to investigate whether BMD explains the odds of membership in a certain oral and cognitive health group. The final models were adjusted for socioeconomic, health, and lifestyle factors.

RESULTS

Our study sample (N = 25,444: 13,035 males, 12,409 females) was grouped into 5 and 4 clusters based on the oral health status and performance on the cognitive tasks, respectively. After adjusting for all potential covariates, increase in BMD was not associated with higher odds of membership in classes with better oral health (odds ratio [OR] = 1.58 [95% confidence interval {CI}: 0.85-2.92]) and cognitive health (OR = 1.61 [95% CI: 1-2.6]) compared with the groups with the least favorable oral and cognitive health status, respectively.

CONCLUSION

Middle-aged and elderly Canadians show different oral and cognitive health profiles, based on their denture-wearing status and performance on cognitive tests. No evidence could be found to support BMD in place of cholinergic neurons' activity as the common explanatory factor behind the association between oral health and cognitive health.

KNOWLEDGE TRANSFER STATEMENT

This study is probably the first of its kind to shed light on the cholinergic system as a potential pathway influencing oral and cognitive health. Our findings may support the notion that any potential association between poor oral health and cognitive health might be explained by common contributors, helping clinicians to find the common risk factors for both conditions.

Have Women Broken the Glass Ceiling in North American Dental Leadership?

In the last few decades, the number of women graduating from North American (NA) dental schools has increased significantly. Thus, we aimed to determine women’s representation in leadership positions in NA dental and specialty associations/organizations, dental education, and dental journals, as well as the proportion of men/women researcher members of the American Association for Dental Research (AADR). We contacted NA dental associations to provide us with the total number and the men/women distribution of their members. Men/women distributions in leadership positions were accessible from the internet, as were data on the sex of deans of NA dental schools. Data on the editors in chief of NA dental journals were gathered from their websites, and the AADR provided the number and sex of its researcher members. Collected data underwent descriptive statistics and binomial tests (α = 0.05). Our findings suggest that women are underrepresented in leadership positions within the major NA dental professional associations. While the median ratio of women leaders to women members in professional associations is 0.91 in Canada, it is only 0.67 in the United States. The same underrepresentation of women is evident in the leadership of the Canadian Dental Association and the American Dental Association. We found that women are underrepresented as deans and editors in chief for NA oral health journals. Only 16 of 77 NA dental school deans are women, while 3 of 38 dental journals have women editors in chief. The probability of finding these ratios by chance is low. However, the number of women dental researcher AADR members underwent an overall increase in the past decade, while the number of men declined. These results suggest that, despite the increase in women dentists, it will take time and effort to ensure that they move through the pipeline to senior leadership positions in the same manner as their male colleagues.

Building Oral Health Research Capacity in India: Identifying Barriers and Enablers Using Mixed Methods

Knowledge Transfer Statement: This article will provide a brief overview of the methods in finding barriers and enablers in doing oral health research in India. This mixed-methods approach can be used by researchers in finding barriers and enablers in doing oral health research in other developing countries and building oral health research capacities.

Chewing Indicators between Adults with Down Syndrome and Controls

Down syndrome induces a neuromotor deficiency that affects the orofacial musculature, and thus could be implicated in the feeding difficulties affecting people with this disease. This study aimed to investigate the differences in chewing indicators between a group of 11 adults with Down syndrome and a group of 12 healthy subjects without Down syndrome. Chewing ability was evaluated by means of video recordings taken during a standardized meal that included 10 natural foods. The variables collected were masticatory time, number of masticatory cycles, chewing frequency, number of open masticatory cycles, and number of food refusals. There were several differences in both directions for masticatory time and number of masticatory cycles between the two groups. In addition, with the exception of purée, the group with Down syndrome had significantly lower mean chewing frequency than the reference group, and was unable to eat all the foods presented.

Efficacy of Mandibular 2-implant Overdenture: An Updated Meta-analysis on Patient-based Outcomes

The extent of heterogeneity regarding the efficacy of the mandibular 2-implant overdenture is still in question. The aim of this meta-analysis is to provide an update on the existing evidence from randomized controlled trials assessing the efficacy of the mandibular 2-implant overdenture in regard to patient-based outcomes. Electronic searches were carried out to September 2015 through MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Systematic Reviews. Only randomized controlled trials that compared conventional dentures with mandibular 2-implant overdentures were included. Patient-based outcomes were assessed, including patient satisfaction and oral health- and general health-related quality of life. Random effects models were used to pool the effect sizes of all included studies. Further stratified analyses and heterogeneity analyses were tested, as was publication bias. In addition to the 7 randomized controlled trials that were included in the previous meta-analysis, 4 new trials were identified and included in this update. A random effects model showed that, when compared with conventional dentures, mandibular 2-implant overdentures significantly improved patient satisfaction (pooled effect size = 0.87, z = 5.31, 95% confidence interval: 0.55 to 1.19, P < 0.0001, χ² = 41.82, df = 8, P < 0.0001, I² = 81%) and oral health-related quality of life (pooled effect size = -0.66, z = 2.72, 95% confidence interval: -1.13 to -0.18, P = 0.007, χ² = 21.26, df = 4, P = 0.0003, I² = 81%). The differences in participant recruitment and their pretreatment condition were important sources of heterogeneity among the studies. Only 1 study investigated the impact of mandibular implant overdentures on perceived general health, and it revealed no between-treatment differences. The 2-implant mandibular overdenture improves patient satisfaction and quality of life for the general edentate population. Health status, poor oral condition, and patient characteristics may effect patient-based outcomes and should be considered by clinicians in treatment planning. Knowledge Transfer Statement: This meta-analysis shows that mandibular 2-implant overdentures are significantly more satisfactory to the general edentate populations than new conventional dentures. The results also show that mandibular 2-implant overdentures provide significantly better oral health-related quality of life than do new conventional dentures. These results should be shared with edentate patients in planning their treatment.

Tooth Loss Increases the Risk of Diminished Cognitive Function

Emerging evidence suggests that oral health is associated with cognitive function. This review aims to systematically assess this association in adult populations via prospective cohort study designs. Eligible study reports were identified by searching the MEDLINE (via Ovoid), EMBASE, PsycoINFO, and Cochrane Library databases. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated with a random effects model. From 1,251 identified articles, 10 were included in the systematic review and 8 in the meta-analysis. Random effects analysis showed, with statistically low heterogeneity, that individuals with suboptimal dentition (<20 teeth) were at a 20% higher risk for developing cognitive decline (HR = 1.26, 95% CI = 1.14 to 1.40) and dementia (HR = 1.22, 95% CI = 1.04 to 1.43) than those with optimal dentition (≥20 teeth). Studies on the association between periodontal disease and cognitive status showed conflicting results. Within the limits of the quality of published evidence, this meta-analysis lends further support to the hypothesis that tooth loss is associated with an increased risk of cognitive impairment and dementia.

Knowledge Transfer Statement: Based on the published literature, the results of this study show that the risk for cognitive impairment and dementia increases with loss of teeth. This information adds to the evidence showing links between oral and general health and suggests that oral health strategies aimed to preserve teeth may be important in reducing risk of systemic disease.

The role of professional diagnostic delays in the prognosis of upper aerodigestive tract carcinoma

Despite the belief that cancer mortality can be reduced if lesions are detected, diagnosed and treated at an early stage, only one study, among a number concerning cancers of the upper aerodigestive tract (UADT), has found any relationship between such delays and prognosis for this population of cancer patients. The aim of this study was, therefore, to investigate the relationship between patient and professional diagnostic delays and patient prognosis in a group of UADT cancer patients. Patients diagnosed with squamous cell carcinoma of oral cavity sites (ICD-9 141, 143-5)oro-, naso- and hypopharynx (ICD-9 146-8) and larynx (ICD-9 161) were included in the study. Stepwise multiple logistic regression was used to calculate the odds ratio (OR) of late versus early stage disease for selected study variables. The sample comprised 188 subjects. Multivariate analysis found that having a pharyngeal cancer (OR 9.26; 95% CI 4.02-21.32; P: 0.0001) a professional delay > 1 month (OR 2.28; 95% CI 1.13-4.64; P: 0.022) and age > or = 65 years (OR: 0.45; 95% CI: 0.22-0.91; P: 0.024) were predictive of late stage disease. A dose-response relationship between professional delay and OR for late stage disease for the whole sample (P for trend 0.03) and among those with oral cancer (P for trend 0.0001) was found. The results of this study suggest that, among patients with an UADT cancer, professional delays > 1 month are contributing to an increased risk for being diagnosed with late stage disease.

Predictors of professional diagnostic delays for upper aerodigestive tract carcinoma

In spite of the belief that cancer mortality can be reduced if lesions are detected, diagnosed and treated at an early stage, the predictors of diagnostic delays for upper aerodigestive tract (UADT) cancers have been the subject of little research. The aim of this study was to investigate the role of selected variables as predictors of professional diagnostic delays in a sample of UADT cancer patients. Patients diagnosed with squamous cell carcinoma of oral cavity sites (ICD-9 141, 143-5) oro-, naso- and hypopharynx (ICD-9 146-8) and larynx (ICD-9 161) were included in the study. Multiple logistic regression was used to calculate the odds ratio (OR) for professional delay > 1 month versus professional delay < 1 month for selected study variables. The sample comprised 188 subjects. Multivariate analysis found that the presence of comorbidity at the time of presentation of UADT symptoms (OR 2.84; 95% CI 1.35-5.98), age > or = 65 years (OR 0.31; 95% CI 0.15-0.64), higher education (OR 0.45; 95% CI 0.22-0.93) and cancer at an oral cavity site (OR 0.31; 95% CI 0.15-0.64) were the explanatory variables for professional delay. This study suggests that, among UADT cancer patients, the presence of comorbidity at the time of presentation increases the odds for a professional delay > 1 month, while older age, higher education and oral cancer reduce the odds.