Oral health and healthy chewing for healthy cognitive ageing: A comprehensive narrative review.

INTRODUCTION: Ageing leads to physiological cognitive decline that it is worsened in people with neurodegenerative diseases such as Alzheimer's disease. Despite the ongoing search for a solution to this cognitive decline, no effective remedies have been established. It has been determined that modifiable external factors, such as oral health and occlusal function, prevent cognitive decline. OBJECTIVE: To analyse the primary interactions between occlusal function and cognitive functions. MAIN FINDINGS: Masticatory function is related to cognitive functions. In particular, current evidence, from both animal and human studies, suggests that the activation of masticatory muscles and proper mastication, with natural teeth or dental prosthesis, induces the release of several mediators and the activation of specific brain areas. Together, they result in higher neuronal activity, neurotrophic support, blood flow and the prevention of amyloid-beta plaque formation. Thus, all the components of the masticatory system must work together in order to preserve cognitive function. CONCLUSIONS: Available evidence suggests that oral and cognitive health are more interconnected than previously thought. Therefore, maintenance and adequate restoration of the whole masticatory system are important for the prevention of cognitive decline. In summary, oral and chewing health lead to healthy cognitive ageing.

An update of knowledge on PD-L1 in head and neck cancers: Physiologic, prognostic and therapeutic perspectives.

Programmed cell death-ligand 1 (PD-L1) is a transmembrane protein that acts as a co-inhibitory factor in the immune response. Its receptor, programmed cell death protein 1 (PD-1), is found on immune cells, where binding to PD-L1 can reduce the proliferation of PD-1-positive cells, inhibit their cytokine secretion and induce apoptosis. PD-L1 in immune-privileged tissue plays a crucial role in peripheral tolerance. PD-L1 can be overexpressed in various malignancies, including oral squamous cell carcinoma, where it can attenuate the host immune response to tumour cells and has been associated with a worse prognosis. Monoclonal antibody therapies targeting the PD-1:PD-L1 axis have shown initial promise, but further research is needed to identify which patients will benefit. We provide an update of knowledge on PD-L1, including its structure, function and regulation. We also review studies on the overexpression of PD-L1 in cancer, specifically oral squamous cell carcinoma, and explore its potential value as a therapeutic target.

Systemic inflammatory impact of periodontitis on cognitive impairment.

OBJECTIVES: The role in dementia of systemic inflammation derived from periodontal disease is not fully elucidated. The objective of our study was to examine the impact of inflammation on the relationship between periodontitis and cognitive impairment. METHODS: We have designed a case (n = 171) and control (n = 131) study to determine the periodontal health status, grade of cognitive impairment/dementia and systemic inflammation level, the last being measured by analysis of 29 inflammatory biomarkers using multiplex techniques. RESULTS: At the time of sampling, 11 of the 29 inflammatory biomarkers were associated with cognitive impairment in patients with more severe periodontitis. However, the inflammatory response to severe periodontitis was more reduced (lower biomarker concentrations) in cases (with cognitive impairment or dementia) than in (cognitively healthy) controls, an unexpected finding. CONCLUSIONS: Based on these results, we cannot confirm that systemic inflammation derived from periodontal disease plays a relevant role in the aetiology of cognitive impairment.

An update of knowledge on cortactin as a metastatic driver and potential therapeutic target in oral squamous cell carcinoma.

Cortactin is a protein encoded by the CTTN gene, localized on chromosome band 11q13. As a result of the amplification of this band, an important event in oral carcinogenesis, CTTN is also usually amplified, promoting the frequent overexpression of cortactin. Cortactin enhances cell migration in oral cancer, playing a key role in the regulation of filamentous actin and of protrusive structures (invadopodia and lamellipodia) on the cell membrane that are necessary for the acquisition of a migratory phenotype. We also analyze a series of emerging functions that cortactin may exert in oral cancer (cell proliferation, angiogenesis, regulation of exosomes, and interactions with the tumor microenvironment). We review its molecular structure, its most important interactions (with Src, Arp2/3 complex, and SH3-binding partners), the regulation of its functions, and its specific oncogenic role in oral cancer. We explore the mechanisms of its overexpression in cancer, mainly related to genetic amplification. We analyze the prognostic implications of the oncogenic activation of cortactin in potentially malignant disorders and in head and neck cancer, where it appears to be relevant in the development of lymph node metastasis. Finally, we discuss its usefulness as a therapeutic target and suggest future research lines.

Oral and general health-related quality of life in patients treated for oral cancer compared to control group.

BACKGROUND: Health-related quality of life (HRQoL) is gaining importance as a valuable outcome measure in oral cancer area. The aim of this study was to assess the general and oral HRQoL of oral and oropharyngeal cancer patients 6 or more months after treatment and compare them with a population free from this disease. METHODS: A cross-sectional study was carried out with patients treated for oral cancer at least 6 months post-treatment and a gender and age group matched control group. HRQoL was measured with the 12-Item Short Form Health Survey (SF-12); oral HRQoL (OHRQoL) was evaluated using the Oral Health Impact Profile (OHIP-14) and the Oral Impacts on Daily Performances (OIDP). Multivariable regression models assessed the association between the outcomes (SF-12, OHIP-14 and OIDP) and the exposure (patients versus controls), adjusting for sex, age, social class, functional tooth units and presence of illness. RESULTS: For patients (n = 142) and controls (n = 142), 64.1% were males. The mean age was 65.2 (standard deviation (sd): 12.9) years in patients and 67.5 (sd: 13.7) years in controls. Patients had worse SF-12 Physical Component Summary scores than controls even in fully the adjusted model [ß-coefficient = -0.11 (95% CI: -5.12-(-0.16)]. The differences in SF-12 Mental Component Summary were not statistically significant. Regarding OHRQoL patients had 11.63 (95% CI: 6.77-20.01) higher odds for the OHIP-14 and 21.26 (95% CI: 11.54-39.13) higher odds for OIDP of being in a worse category of OHRQoL compared to controls in the fully adjusted model. CONCLUSION: At least 6 months after treatment, oral cancer patients had worse OHRQoL, worse physical HRQoL and similar psychological HRQoL than the general population.

Association between general and oral health-related quality of life in patients treated for oral cancer.

BACKGROUND: Less is known about the association between general health-related quality of life (HRQoL) and oral HRQoL (OHRQoL) among patients with specific diseases. The aim of this study was to assess the association between patient-centered outcome measurements (HRQoL and OHRQoL) of oral cancer patients at least 6 months after treatment. MATERIAL AND METHODS: HRQoL was measured with the 12-Item Short Form Health Survey (SF-12); OHRQoL was evaluated using the Oral Health Impact Profile (OHIP-14) and the Oral Impacts on Daily Performances (OIDP). RESULTS: Higher OHRQoL scores were associated with lower SF-12 domains scores. The OHIP-14 explained 16.5 % of the total variance of SF-12 Physical Component Summary (PCS) and the OIDP explained 16.1 %. In the SF-12 Mental Component Summary (MCS), the total variance explained was 23.9 % by the OHIP-14 and 21.8 % by the OIDP. CONCLUSIONS: There was a significant association between long-term OHRQoL and HRQoL in oral and oropharyngeal cancer patients. These results may help to carry out new interventions aiming to improve patient's life overall.

Evaluation of p53, caspase-3, Bcl-2, and Ki-67 markers in oral squamous cell carcinoma and premalignant epithelium in a sample from Alava Province (Spain).

OBJECTIVE: The objective of this study was to determine whether alterations in the expression of p53, caspase-3 Bcl-2, and ki-67 appear early in premalignant oral epithelium and show clonal behavior. STUDY DESIGN: Samples from 41 tumors with their adjacent non-tumor epithelia were immunohistochemically analyzed using monoclonal antibodies that recognize p53, caspase-3, Bcl-2, and Ki-67 RESULTS: A statistically significant association was found between the expression in tumor and adjacent epithelium of p53, caspase-3, and Bcl-2 but not of k-67. A significant association was observed between the expression of ki-67 and p53 in both localizations. In non-tumor (premalignant) epithelium samples, there was a significant inverse relationship between the expressions of p53 and caspase-3 and a significant direct relationship between the expressions of p53 and Bcl-2. CONCLUSIONS: Alterations in these proteins appear to operate in combination with premalignant epithelia to create hyperproliferative cell states that favor the acquisition of summative oncogenic errors that confer invasive capacity.

Oral health and mortality risk in the institutionalised elderly.

OBJECTIVE: Examining oral health and oral hygiene as predictors of subsequent one-year survival in the institutionalised elderly. DESIGN: It was hypothesized that oral health would be related to mortality in an institutionalised geriatric population. A 12-month prospective study of 292 elderly residing in nine geriatric institutions in Granada, Spain, was thus carried out to evaluate the association between oral health and mortality. Independent samples, T-test, chi-square test and Cox regression analysis were used to analyse the data. Sixty-three participants died during the 12-month follow-up. RESULTS: Mortality was increased in denture users (RR = 2.18, p= 0.007) and in people suffering severe cognitive impairment (RR = 2. 24, p= 0.003). One-year mortality was 50% in participants having both these characteristics. CONCLUSIONS: Oral hygiene was not significantly associated with mortality. Cognitive impairment and wearing dentures increased the risk of death. One-year mortality was 50% in cognitively impaired residents wearing dentures as opposed to 10% in patients without dentures and cognitive impairment.

Association between low bone mineral density and periodontitis in generally healthy perimenopausal women.

BACKGROUND: The association between low bone mineral density (BMD) and periodontitis in perimenopausal women is controversial. The purpose of this study was to determine whether osteoporosis or osteopenia is associated with periodontal disease in a population of adult women. METHODS: A sample of over-45-year-old women with or without low BMD underwent lumbar spine and hip bone densitometry and a complete periodontal examination. The extent/severity or absence of periodontal disease was noted using two different case definitions. Data were gathered on socio-economic status, medication history, systemic co-morbidities, alcohol or tobacco use as well as serum levels of calcium and vitamin D. RESULTS: One hundred seventy three women aged between 45 and 72 years old were recruited with a mean age of 57.8 years. One hundred and three had decreased BMD (61 with osteoporosis and 42 with osteopenia) and 70 were healthy. Moderate or severe periodontitis was present in 52.6% of the women. Multivariate analysis showed a clear association between low BMD and periodontitis, but only in women above 58 years old and independent of tobacco consumption or oral hygiene. CONCLUSION: In this sample of generally healthy perimenopausal women, low BMD was associated with clinical attachment level (CAL). Women over 58 years old with decreased BMD presented with a higher mean percentage of sites with CAL ≥ 4 mm as well as CAL ≥ 6 mm when compared to controls, independent of active smoking status or poor oral hygiene.

A role for the substance P/NK-1 receptor complex in cell proliferation in oral squamous cell carcinoma.

OBJECTIVE: To investigate the presence and distribution of substance P (SP) and neurokinin 1 receptor (NK-1R) in oral squamous cell carcinoma (OSCC) and their relationship with proliferation. PATIENTS AND METHODS: Ninety OSCCs from 73 patients were immunohistochemically analyzed using monoclonal antibodies against SP, NK-1R and Ki-67 in a case and control study. RESULTS: Seventy-one percent (n=49) of cases expressed SP on tumour cell membrane, 81.3% (n=69) in cytoplasm, 39.4% (n=28) in nucleus, 81.6% (n=71) in infiltrating lymphocytes, and 58.1% (n=43) in peritumoural or intratumoural blood vessels; 14% (n=12) of cases expressed NK-1R on tumour cell membrane, 50% (n=43) in cytoplasm, 48.3% (n=42) in infiltrating lymphocytes and 22.5% (n=18) in tumour blood vessels. All cases expressed Ki-67, which was expressed in >25% of tumour cells in 79.8% of cases (n=63). Direct significant associations were observed in SP expression between different tissue levels (p<0.01), between SP and NK-1R tumour cell membrane expression (p<0.01), and between joint SP and NK-1R expression in tumour cell cytoplasm and a higher expression of Ki-67 (p<0.05). CONCLUSION: The ubiquitous presence of SP strongly suggests a role for SP/NK-1R complex in tumour development and progression and possibly for NK-1R antagonists, such as L-773060, in the management of patients with oral cancer.

The influence of habitual consumption of chewing gums in the outcome of masticatory performance tests using two-coloured chewing gums.

The aim of this study is to assess the influence of regular consumption of chewing-gums on the Masticatory Performance (MP); and to determine if increasing the consumption improves the MP of non-regular consumers. We recorded the chewing-gums consumption rate (CGC) and measured the MP of 265 participants (µ = 47.09, σ = 22.49 years) using the Variance of the Histogram of the Hue (VhH) image processing method. Then, participants were instructed to increase the consumption, and the MP was measured again (SESSION) two and four days after. Normality of MP was verified with Kolmogorov-Smirnov and Shapiro-Wilk tests. The association between the age and the consumption rate was measured with GEE and the eta-squared statistic. Finally, a 3 × 3 mixed ANOVA with SESSION as the within-subject factor and CGC as the between-subjects factor was run. Session-wise and group-wise comparison were performed with post hoc Bonferroni. No systematic error was detected for VhH (p = 1.00). Kolmogorov-Smirnov and Shapiro-Wilk tests confirmed the normality of the distribution of MP (p > 0.05). There was a significant effect of SESSION on MP, F(1.746, 457.328) = 59.075, p < 0.001; furthermore, there were significant differences in MP between SESSIONs. Additionally, there was a significant effect of CGC on MP, with F (2, 356.53) = 564.73, p < 0.001. In conclusion, the chewing-gum consumption habits influence the two-coloured chewing gum mixing test. The apparent MP of non-regular consumers can be improved by prescribing a controlled increase in the consumption of chewing-gums for a few days.

Malignant transformation risk of oral lichen planus: A systematic review and comprehensive meta-analysis.

OBJECTIVES: To evaluate current evidence on the malignant transformation of oral lichen planus (OLP), oral lichenoid lesions (OLLs), and oral lichenoid reactions (LRs) and to determine the variables with greatest influence on cancer development. MATERIAL AND METHODS: We searched PubMed, Embase, Web of Science, and Scopus for studies published before November 2018. We evaluated the quality of studies (QUIPS tool). We carried out meta-analyses to fulfill our objectives. We examined the between-study heterogeneity and small-study effects, and conducted sensitivity studies and subgroup analyses. RESULTS: Inclusion criteria were met by 82 studies (26,742 patients. The combined malignant transformation rate was 1.14% for OLP (95% CI = 0.84-1.49), 1.88% for OLLs (95% CI = 0.15-4.95) and 1.71% for LRs (95% CI = 0.00-5.46). Subgroup analysis revealed a higher malignant transformation rate in studies when the presence of epithelial dysplasia was not an exclusion criterion (p = 0.001), when both clinical and histopathological criteria were used for diagnosis (p < 0.001), when the follow-up was at least 12 months (p = 0.048), and when there was lower risk of potential bias (p = 0.002). Malignant transformation risk factors were: tongue localization (RR = 1.82, 95% CI = 1.21-2.74, p = 0.004), presence of atrophic-erosive lesions (RR = 4.09, 95% CI = 2.40-6.98, p < 0.001), tobacco use (RR = 1.98, 95% CI = 1.28-3.05, p = 0.002), alcohol consumption (RR = 2.28, 95% CI = 1.14-4.56, p = 0.02), and hepatitis C virus infection (RR = 4.46, 95% CI = 0.98-20.22, p = 0.053). CONCLUSIONS: The malignant transformation rates of OLP, OLLs and LRs are underestimated due essentially to restrictive diagnostic criteria, inadequate follow-up periods, and/or low quality of studies.

Predictive value of CCND1/cyclin D1 alterations in the malignant transformation of potentially malignant head and neck disorders: Systematic review and meta-analysis.

BACKGROUND: To evaluate published evidence on the predictive value of CCND1 amplification/cyclin D1 overexpression as malignant transformation risk markers in potentially malignant disorders (PMDs) of the head and neck. MATERIAL AND METHODS: We searched PubMed, Embase, Web of Science, and Scopus for studies published before June 2018. We conducted a meta-analysis to quantify the impact of CCND1/cyclin D1 amplification/overexpression on malignant transformation of head and neck PMDs. RESULTS: Nine studies met inclusion criteria. Quantitative evaluation indicated strong statistically significant association between CCND1/cyclin D1 amplification/overexpression and the progression of head and neck PMD to head and neck squamous cell carcinoma (risk ratio [RR] = 2.04, 95% confidence interval [CI] = 1.37-3.03, P < .001, and RR = 2.27, 95% CI = 1.32-3.91, P = .003, respectively). We observed moderate heterogeneity among studies (I2 = 40.7%), and we cannot rule out small-study effects such as publication bias. The oral cavity subgroup showed the strongest association between CCND1/cyclin D1 amplification/overexpression and progression to cancer. CONCLUSION: CCND1/cyclin D1 amplification/overexpression is important to predict the malignant transformation risk of head and neck PMDs, especially oral PMDs.

Prognostic and clinicopathological significance of CTTN/cortactin alterations in head and neck squamous cell carcinoma: Systematic review and meta-analysis.

BACKGROUND: To evaluate the prognostic significance of CTTN/cortactin alterations in head and neck squamous cell carcinoma (HNSCC). MATERIAL AND METHODS: We searched PubMed, Embase, Web of Science, and Scopus for studies published before May 2018. We conducted a meta-analysis to quantify the impact of CTTN/cortactin alterations on clinicopathological and survival variables. RESULTS: Eighteen studies (1633 patients) met inclusion criteria. Quantitative evaluation revealed a strong association of CTTN/cortactin alterations with N+ status (P < .001), higher T status (P < .001), advanced clinical stage (P < .001), high histological grade (P = .001), and lower overall survival (OS) (P < .001). We found heterogeneity in T status, histological grade, and OS and observed small-study effects on N status and OS. In subgroup analyses, a significant association of CTTN amplification and cortactin overexpression with the above variables was preserved. The strongest association between CTTN/cortactin alterations and a worse outcome was observed in the subgroups of Asian patients and pharyngolaryngeal squamous cell carcinomas. CONCLUSIONS: CTTN/cortactin alterations should be evaluated to predict the HNSCC prognosis.

Clinicopathological significance of tumor cyclin D1 expression in oral cancer.

OBJECTIVE: To evaluate the association of cyclin D1 overexpression with clinicopathological parameters classically considered of prognostic value in OSCC (T, N, M, clinical stage, degree of differentiation, invasive morphology and, cellular proliferation index). DESIGN: A retrospective immunohistochemical study was conducted of cyclin D1 and ki-67 expression in 68 OSCCs from 54 patients. Cases were scanned using a digital pathology system. The tumor expression of markers was assessed in four randomly selected fields (40x), and a semi-automatized count was conducted of cyclin D1-positive and -negative cells. RESULTS: Cyclin D1 overexpression was found in 28.7% of the cases of OSCC. It was significantly and positively associated with the following clinicopathological parameters: low tumor differentiation degree (p = 0.030), invasive morphology (p = 0.045), and proliferative phenotype according to tumor cell ki-67 expression (p = 0.018). CONCLUSIONS: Cyclin D1 overexpression is an event of oral carcinogenesis associated with clinicopathological parameters classically associated with a poor prognosis in patients with OSCC.

Asymmetrical proliferative pattern loss linked to cyclin D1 overexpression in adjacent non-tumour epithelium in oral squamous cell carcinoma.

OBJECTIVE: To evaluate cyclin D1 overexpression in oral squamous cell carcinomas and adjacent non-tumour epithelium as a biomarker of premalignant fields and a risk factor for multiple tumour development. DESIGN: We studied cyclin D1 expression in 54 patients with 68 oral squamous cell carcinomas plus adjacent non-tumour epithelia characterized as close (n = 58) or distant (n = 41) from the invasion point. Randomized 40x fields were evaluated (4 in tumour tissue and 1 each in close and distant non-tumour epithelium). Expression in non-tumour epithelium was evaluated in basal, parabasal, middle-third and upper-third compartments. RESULTS: Cyclin D1 overexpression was found in both carcinomas and non-tumour epithelia. Nuclear expression in basal and parabasal layers of distant epithelium was significantly increased in patients with multiple tumours (p < 0.001). A significant association between cyclin D1 overexpression in different epithelial layers was found in both close and distant epithelia. A significant association was found between nuclear expressions of cyclin D1 and Ki-67 in the basal layer of distant epithelium (p = 0.02). CONCLUSIONS: Cyclin D1 overexpression is an early event in oral carcinogenesis linked to loss of the physiological asymmetrical proliferation pattern. Cyclin D1 overexpression in basal and parabasal layers of epithelia distant from the invasion point may act as a potential marker of premalignant fields and multiple tumour development.

A novel expert system for objective masticatory efficiency assessment.

Most of the tools and diagnosis models of Masticatory Efficiency (ME) are not well documented or severely limited to simple image processing approaches. This study presents a novel expert system for ME assessment based on automatic recognition of mixture patterns of masticated two-coloured chewing gums using a combination of computational intelligence and image processing techniques. The hypotheses tested were that the proposed system could accurately relate specimens to the number of chewing cycles, and that it could identify differences between the mixture patterns of edentulous individuals prior and after complete denture treatment. This study enrolled 80 fully-dentate adults (41 females and 39 males, 25 ± 5 years of age) as the reference population; and 40 edentulous adults (21 females and 19 males, 72 ± 8.9 years of age) for the testing group. The system was calibrated using the features extracted from 400 samples covering 0, 10, 15, and 20 chewing cycles. The calibrated system was used to automatically analyse and classify a set of 160 specimens retrieved from individuals in the testing group in two appointments. The ME was then computed as the predicted number of chewing strokes that a healthy reference individual would need to achieve a similar degree of mixture measured against the real number of cycles applied to the specimen. The trained classifier obtained a Mathews Correlation Coefficient score of 0.97. ME measurements showed almost perfect agreement considering pre- and post-treatment appointments separately (κ ≥ 0.95). Wilcoxon signed-rank test showed that a complete denture treatment for edentulous patients elicited a statistically significant increase in the ME measurements (Z = -2.31, p < 0.01). We conclude that the proposed expert system proved able and reliable to accurately identify patterns in mixture and provided useful ME measurements.

Prognostic and clinicopathological significance of cyclin D1 expression in oral squamous cell carcinoma: A systematic review and meta-analysis.

OBJECTIVES: To evaluate the prognostic significance of cyclin D1 (CD1) overexpression in OSCC. MATERIAL AND METHODS: We searched studies published before August 2017 (Pubmed, Embase, Web of Science, Scopus). We evaluated the quality of the studies included (Quality in Prognosis Studies [QUIPS] tool). The impact of CD1 overexpression on overall survival and disease-free survival, T status, N status, stage, and histological degree was meta-analyzed. We analyzed heterogeneity among studies, conducted sensitivity analyses, analyzed small-study effects, and conducted subgroup analyses. RESULTS: 31 studies (2942 patients) met inclusion criteria. Qualitative evaluation demonstrated that not all studies were performed with the same rigor, finding the greatest risk of bias in the study confounding domain. Quantitative evaluation showed that CD1 overexpression had a strong statistical association with worse overall survival (HR = 2.00, 95% CI = 1.59-2.51, p < 0.001), worse disease-free survival (HR = 1.46, 95% CI = 1.13-1.87, p = 0.003), higher T status (OR = 1.51, 95% CI = 1.07-2.13, p = 0.02), N+ status (OR = 2.16, 95% CI = 1.60-2.92, p < 0.001), advanced stage (OR = 1.44, 95% CI = 1.15-1.81, p = 0.002), and high histological grade (OR = 1.60, 95% CI = 1.12-2.29, p = 0.010). We observed heterogeneity in all parameters except for disease-free survival and clinical stage. We found effect of small studies on T and N status. The tonguel SCC subgroup showed the strongest association between CD1 overexpression and worse development. In addition, application of a cutoff point ≥10% tumor cells with nuclear CD1 expression maintained most of the significant associations reported. CONCLUSIONS: These findings indicate that immunohistochemical assessment of CD1 overexpression may be useful as a prognostic biomarker for OSCC.

Association Between Periodontitis and Amyloid ß Peptide in Elderly People With and Without Cognitive Impairment.

BACKGROUND: Evidence that periodontal disease is a possible risk factor for cognitive impairment may be explained by the inflammatory hypothesis. The aim of this study is to determine whether periodontitis is related to the amyloid ß (Aß) load in blood and the role of any such relationship in the association between Aß and cognitive impairment. METHODS: A case-control study was performed in elderly people diagnosed with cognitive impairment with or without dementia (cases group) and cognitively healthy elderly people (control group); data were collected on the medical and dental history of participants, and blood samples were drawn to determine Aß levels using enzyme-linked immunosorbent assay. RESULTS: The study included 166 patients and 122 control participants. Higher blood Aß1-42 levels (P = 0.01) and higher Aß42:40 ratio (P = 0.06) were observed in participants with severe attachment loss than in other participants. Periodontitis was a significant interaction variable, given that the association between Aß1-42 and Aß1-40 and cognitive impairment was only observed in patients with severe periodontitis. According to these data, periodontitis may be a modulating variable of the association between Aß and cognitive impairment. CONCLUSIONS: Plasma Aß1-42 levels are higher in individuals who have severe periodontal disease. The presence of periodontitis may modify the association between Aß and cognitive impairment.

Oral Hygiene in the Elderly with Different Degrees of Cognitive Impairment and Dementia.

The control of bacterial dental plaque through daily oral hygiene is essential to prevent oral diseases such as caries or periodontal disease, especially in at-risk populations, including the elderly with mild cognitive impairment and dementia. The aim of this study was to determine the association between different levels of cognitive impairment and dementia in an elderly population and their capacity to maintain adequate oral hygiene. A case-control study (elderly with versus without mild cognitive impairment or dementia) was performed in Granada, Spain. Outcome variables were tooth/prosthesis-brushing frequency/day, bacterial plaque index, and gingival bleeding index. Statistical models were adjusted by age, sex, educational level, and tobacco and alcohol habits. The study included 240 cases and 324 controls. The final model, adjusted by age, sex, educational level, and tobacco and alcohol consumption, showed a significant association between degree of cognitive impairment and daily oral hygiene, accumulation of bacterial plaque, and gingival bleeding. In summary, deficient daily oral hygiene, evidenced by greater bacterial dental plaque accumulation and gingival inflammation, is independently associated with cognitive impairment, even at its earliest stage.