Roxane Weijenberg

Mastication for the mind—The relationship between mastication and cognition in ageing and dementia

The goal of this literature review has been to investigate the relationship between mastication and cognition, with a special focus on ageing and dementia, and its possible underlying mechanisms. Since the relationship between mastication and cognition is not yet firmly established, and is investigated in the context of a number of different disciplines, a comprehensive overview will contribute to our knowledge. The results of animal and human experimental studies suggest a causal relationship between mastication and cognition. Furthermore, correlations exist between mastication and activities of daily living and nutritional status. These findings have compelling implications for the development of prevention strategies by which medical and nursing staff may optimize their care for the frail and elderly, suffering from dementia.

Two‐colour chewing gum mixing ability: digitalisation and spatial heterogeneity analysis

Many techniques are available to assess masticatory performance, but not all are appropriate for every population. A proxy suitable for elderly persons suffering from dementia was lacking, and a two-colour chewing gum mixing ability test was investigated for this purpose. A fully automated digital analysis algorithm was applied to a mixing ability test using two-coloured gum samples in a stepwise increased number of chewing cycles protocol (Experiment 1: n = 14; seven men, 19-63 years), a test-retest assessment (Experiment 2: n = 10; four men, 20-49 years) and compared to an established wax cubes mixing ability test (Experiment 3: n = 13; 0 men, 21-31 years). Data were analysed with repeated measures anova (Experiment 1), the calculation of the intraclass correlation coefficient (ICC; Experiment 2) and Spearmans rho correlation coefficient (Experiment 3). The method was sensitive to increasing numbers of chewing cycles (F5,65 = 57·270, P = 0·000) and reliable in the test-retest (ICC value of 0·714, P = 0·004). There was no significant correlation between the two-coloured gum test and the wax cubes test. The two-coloured gum mixing ability test was able to adequately assess masticatory function and is recommended for use in a population of elderly persons with dementia.

Increased masticatory activity and quality of life in elderly persons with dementia-a longitudinal matched cluster randomized single-blind multicenter intervention study

BackgroundWorldwide, millions of people are suffering from dementia and this number is rising. An index of quality of life (QoL) can describe the impact a disease or treatment has on a person’s wellbeing. QoL comprises many variables, including physical health and function, and mental health and function. QoL is related to masticatory ability and physical activity. Animal studies show that disruption of mastication due to loss of teeth or a soft diet leads to memory loss and learning problems. Since these are common complaints in dementia, it is hypothesized that improvement of masticatory function and normalization of diet consistency can increase QoL in elderly persons suffering from dementia. Therefore, the goal of the present study is to examine whether an increase in masticatory activity, achieved by increased food consistency and enhancement of masticatory function through improved oral health care has a positive effect on QoL, including cognition, mood, activities of daily living (ADL), and circadian rhythm in elderly persons with dementia.Methods and designThe described study is a prospective longitudinal matched cluster randomized single-blind multicenter study. Participants are elderly persons living in the Netherlands, suffering from dementia and receiving psychogeriatric care. An intervention group will receive improved oral health care and a diet of increased consistency. A control group receives care as usual. Participants will be assessed four times; outcome variables besides QoL are cognition, mood, independence, rest-activity rhythm, blood pressure, and masticatory function.DiscussionThis research protocol investigates the effect of an intervention executed by daily caregivers. The intervention will increase masticatory activity, which is achieved by three different actions, (providing oral health care, increasing food consistency, or a combination of both). There is a certain amount of variety in the nature of the interventions due to local differences in nursing homes. This might be a scientific weakness in the study design; however, a practical implementation of any findings will be subject to the same factors, making this study design clinically relevant.Trial registrationNTR1561

Chew the Pain Away: Oral Habits to Cope with Pain and Stress and to Stimulate Cognition

The acute effects of chewing gum on cognitive performance, stress, and pain have been intensively studied in the last decade. The results have been contradicting, and replication studies proved challenging. Here, we review some of the recent findings of this topic and explore possible explanations for these discrepancies by incorporating knowledge derived from studies into oral habits and bruxism. Both stress and cerebral functional specialization (i.e., the involvement of specific brain structures in distinctive cognitive processes) are hypothesized to play a major role in the underlying physiological mechanisms of the diverse effects of chewing gum on cognition, stress, and pain.

Denk aan je tanden: de relatie tussen kauwen en cognitie

Elderly persons, especially those suffering from dementia, are at great risk of suffering from oral health problems such as orofacial pain and loss of natural teeth. A possible explanation could be that the cognitive and motor impairments resulting from dementia cause a decrease in self-care and as such, a worsening of oral health. An alternative explanation is that cognition and oral health influence each other. Animal studies show that a decrease in masticatory activity, for example due to a soft diet or loss of teeth, causes memory loss and neuronal degeneration. The relationship between mastication and cognition has also been researched in human studies, but a cause-effect relationship is not yet evident. It is likely that multiple factors play a role in this relationship, such as self-care, nutrition, stress and pain.

Orofacial Pain and Mastication in Dementia

Orofacial pain is a common condition in the general population. It is likely that this is also the case in older persons with a dementia. However, the assessment of (orofacial) pain in non-verbal individuals is hampered by the subjective nature of pain, and their limited communicative abilities. To overcome this drawback, several tools have been developed for the assessment of pain based on observations of pain-specific facial activities, body movements, and vocalizations. Unfortunately, none of the so far developed observational tools have been designed specifically for the assessment of orofacial pain. While the recent psychometric testing of the Orofacial MOBID Pain Scale did not yield reliable outcomes, the subsequently developed Orofacial Pain Scale for Non-Verbal Individuals (OPS-NVI) is currently being evaluated and shows good promise to be reliable and valid. Besides the assessment of orofacial pain, an important application of this instrument will be the investigation of the probable causal association between impaired chewing and cognitive decline, in which orofacial pain plays a mediating role by its negative influence on chewing ability. The identification of this negative influence will urge opinion leaders and policy makers to improve the oral health status in older persons with a dementia. Ultimately, pain-free oral functioning may lead to a higher quality of life and might help stabilizing or improving cognition in this frail and vulnerable patient population.

Orofacial Pain During Rest and Chewing in Dementia Patients Admitted to Acute Hospital Wards: Validity Testing of the Orofacial Pain Scale for Non-Verbal Individuals

AIMS To assess the validity of the resting and chewing components of the recently developed observational diagnostic tool, the Orofacial Pain Scale for Non-Verbal Individuals (OPS-NVI). METHODS This cross-sectional observational study was carried out in two UK hospitals. A total of 56 participants with dementia who were admitted to the acute hospital were observed for 3 minutes during rest and during chewing, and the OPS-NVI was used to identify orofacial pain. Afterwards, the participants were asked about the presence of orofacial pain using self-report pain scales. The sensitivity, specificity, and area under the receiver operating curve (AUROC) of the OPS-NVI were calculated for each activity. Spearman coefficient was calculated to assess the correlation between the number of positively scored behavior items of the OPS-NVI and the presence of orofacial pain according to self-report. RESULTS According to the OPS-NVI, orofacial pain was present in 5.4% of participants during rest and in 9.1% during chewing. According to self-report, the prevalence of orofacial pain was 5.4% during rest and 10.7% during chewing. The specificity of the OPS-NVI was 98.1% to 100%, the sensitivity was 66.7% to 83.3%, and the AUROC was 0.824 to 0.917. The predictive validity showed a strong correlation (0.633 to 0.930, P < .001) between the number of positive behavior items and the self-reported presence of orofacial pain. CONCLUSION The resting and chewing components of the OPS-NVI showed promising concurrent and predictive validity. Nevertheless, further validation is required and highly recommended.