Annali di Stomatologia | 2026; 17(2): 438-449

ISSN 1971-1441 | DOI: 10.59987/ads/2026.2.438-449

Articles

Correlation between cognitive impairment and oral health in the elderly in Southern Italy: a cross-sectional study

Martina Ferrillo¹, Dario Calafiore², Eda Fani³, Enrico Cataneo¹, Antonella De Cicco¹, Mario Migliario⁴, Alfredo De Rosa⁵, Alessandro de Sire^6,7, Leonzio Fortunato¹

¹Dentistry Unit, Department of Health Sciences, University of Catanzaro “Magna Graecia”, Catanzaro, Italy

²Physical Medicine and Rehabilitation Unit, Department of Neurosciences, ASST Carlo Poma, Mantova, Italy

³Department of Life, Health and Environmental Sciences, Postgraduate School of Orthodontics, University of L’Aquila, L’Aquila, Italy

⁴Translational Medicine Department, Università del Piemonte Orientale, Novara, Italy

⁵Department of Life Science, Health and Health Professions, Link Campus University, Rome, Italy

⁶Physical and Rehabilitative Medicine Unit, Department of Medical and Surgical Sciences, University of Catanzaro “Magna Graecia”, Catanzaro, Italy

⁷Research Center on Musculoskeletal Health, MusculoSkeletalHealth@UMG, University of Catanzaro “Magna Graecia”, Catanzaro, Italy

^*Corresponding author: Martina Ferrillo - Email: martina.ferrillo@unicz.it

Article History

Received: May 2, 2026

Accepted: June 20, 2026

Published: June 30, 2026

Abstract

Aim

Cognitive impairment is a chronic disease characterized by a decline in memory, attention, learning, executive ability, and other cognitive functions that occurs with age. Specifically, the late-life cognitive decline ranges from normal, through mild cognitive impairment [MCI], to dementia as the most severe form. Older adults with cognitive impairment may present several related disorders, such as cardiovascular, musculoskeletal, and oral diseases. On the other hand, studies suggested an association between oral health problems and the development of dementia. Therefore, the present multicenter observational cross-sectional study aimed to investigate the correlation between oral health and cognitive status in older adults.

Methods

We included patients aged 65 years or older. Anamnestic and demographic data, including sex and age, were collected. Oral health and cognitive status were evaluated by the Geriatric Oral Health Assessment Index [GOHAI] and the Trail Making Test, respectively.

Results

The predictive values of cognitive deterioration are represented by reduction of the vertical dimension [OR = 1.60; 95% CI: 0.52–4.89] reduction in muscle coordination [OR = 10.10; 95% CI: 2.87–39.80], Newton’s stomatitis [OR = 3.68; 95% CI: 1.14–13.15], reversal clenching [OR = 1.38; 95% Cl: 0.47–3.89], and GOHAI test [OR = 4.83; 95% CI: 1.47–16.52].

Conclusion

In light of our results, oral health seemed to be associated with cognitive decline in older adults. This finding reinforces the importance of early identification and tailored management of oral care in older adults based on objective data; in particular, to better identify patients at high risk, guiding the prescription of preventive strategies to reduce the onset of oral diseases and optimizing resources.

Keywords: older adults/elderly; cognitive impairment; oral health; GOHAI; oral health-related quality of life.

1. Introduction

Cognitive functioning is a key indicator of overall individual health, and cognitive impairment is a chronic disease characterized by a decline in memory, attention, learning, executive ability, and other cognitive functions that occurs with age [1–5]. Specifically, the late-life cognitive decline ranges from normal, through mild cognitive impairment (MCI), to dementia as the most severe form [6]. In fact, perception, processing speed, attention, memory, and executive function deteriorate during aging; thus, cognitively healthy elderly subjects also have complaints in the ability to acquire, consolidate, and remember new information, with a great impact on patients’ quality of life (QoL) and caregivers [7–11]. Older adults with cognitive impairment may present several related disorders, such as cardiovascular, musculoskeletal, and oral diseases [12].

In this context, oral health problems are compounded with impaired self-care, frailty, polypharmacy, co-existing morbidity, malnutrition, and dysphagia [13–16]. Poor health is highly prevalent among the elderly and impacts oral health-related quality of life (OHRQoL) [17]. Caries, periodontal disease, reduced salivary flow, and oral candidiasis are common oral health conditions in older people [18–20], and several studies showed that the elderly who develop dementia reported an increased risk of developing oral health diseases as a result of a decline in self-care and motor skills [21–22]. Poor oral health may contribute to increasing frailty through multiple pathways, which include functional pathways, as poor oral health and inadequate dentition are inversely related to dietary intake [23–24]. As well, a reduced number of teeth is associated with less consumption of fruits and vegetables, a decrease in the intake of proteins and micronutrients, and an increase in the consumption of carbohydrates [25].

On the other hand, studies suggested an association between oral health problems and the development of dementia, reporting that tooth loss and periodontitis might be risk factors for cognitive decline with a causality relationship that remains unclear [26–31]. To the best of our knowledge, the impact that cognitive status might have on oral health in older people and vice versa is still debated. Therefore, the present multicenter observational cross-sectional study aimed to investigate the correlation between oral health and cognitive status in older adults.

2. Materials and methods

2.1 Study design and participants

In this multicenter observational cross-sectional study, we recruited patients aged more than 65 years and excluded patients with the following criteria: a) suffering from genetic diseases [e.g., Prader-Willi Syndrome, Down Syndrome, etc.]; b) in treatment with corticosteroids, immunoglobulin, or immunosuppressive drugs; c) suffering from major concurrent diseases; d) fully edentulous patients.

The Ethical Committee of Calabria Region approved this study. Elderly subjects with moderate-severe cognitive impairment were assisted by their caregivers in answering the questions to avoid distortion of information. The study was performed in accordance with the “Strengthening the Reporting of Observational Studies in Epidemiology” [STROBE] guidelines for cross-sectional studies [32] and respected the Declaration of Helsinki, with pertinent national and international regulatory requirements. All participants/caregivers provided written informed consent and were free to withdraw from the study at any time [33].

2.2 Data collection and outcome measures

Anamnestic and demographic data, including sex and age, were collected.

Using the 10-item Short Portable Mental Status Questionnaire (SPMSQ), patients were stratified in relation to the presence [SPMSQ ≥ 5] or absence of moderate-severe cognitive deficit (SPMSQ ≤ 2).

The Geriatric Oral Health Assessment Index (GOHAI) was administered as the main outcome. Moreover, the following secondary outcome measures were collected: Braden Index and Trail Making Test (TMT).

Cognitive status was measured using a 10-item SPMSQ. For SPMSQ scoring, 0–2 indicated complete cognitive function, 3–4 indicated mild cognitive functional impairment, 5–7 indicated moderate cognitive function impairment, and 8–10 indicated severe cognitive function impairment; this assessment should be based on the education level [34]. Specifically, if the education level was primary school and below, 0 to 3 errors were considered as good cognitive function; 4 to 5 errors were considered as mild cognitive decline; 6 to 8 errors were considered as moderate cognitive decline, and 9 to 10 errors were considered as severe cognitive decline. If the education level was middle school, 0 to 2 errors were considered as good cognitive function; 3 to 4 errors were considered as mild cognitive decline; 5 to 7 errors were considered as moderate cognitive decline, and 8 to 10 errors were considered as severe cognitive decline. If the education level was high school and above, 0 to 1 errors were considered as good cognitive function; 2 to 3 errors were considered as mild cognitive decline; 4 to 6 errors were considered as moderate cognitive decline, and 7 to 10 errors were considered as severe cognitive decline [35].

The GOHAI is a validated index used to detect the oral health status in elderly patients. It includes 12 questions, each with a score between 1 and 5, and a cumulative score ranging from 12 to 60. A higher score indicates a better perceived oral health status. According to Sanchez-Garcia et al. [36], GOHAI is divided into three categories: physical function, psychosocial function, and pain and discomfort. Of the 12 questions, four questions evaluate physical functions, including eating, speaking, and associated swallowing; five questions evaluate psychosocial function, including worries about oral health, dissatisfaction with appearance, self-consciousness about oral health, and difficulty with social contacts owing to oral conditions; and three questions evaluate pain and discomfort, including the use of medication to alleviate pain in the oral cavity [37].

The Braden Scale is a validated tool to assess the nutritional status and risk of developing pressure ulcers [38]. The scale includes measures of six domains: sensory perception and communication, moisture, activity, mobility, nutrition, and skin friction + shear. Each domain is scored separately and summed to derive a total score ranging from 6 to 23. Lower scores correlate to a higher risk of pressure ulcer with a suggested threshold value of 18 [39]. The trail making test (TMT) is a useful tool for assessing executive function, consisting of two subtests: in TMT-A, the responder is asked to connect randomly positioned circles containing numbers from 1 to 25 following the number sequence [40]; in TMT-B, the patient is asked to alternate between numbers and letters. In both cases, scores are calculated by measuring time required to complete the tasks and the TMT-B minus TMT-A difference is calculated. Graph motor speed and visual scanning are important in performing both TMT-A and TMT-B, while executive function is more specifically involved in TMT-B [41].

2.3. Statistical analysis

Data management and analyses were conducted according to a prespecified statistical analytical plan. The descriptive characteristics (socio-demographic and geriatric data) of the population included in the study, resulting from the administration of the questionnaires and the clinical visit, were stratified in relation to the presence (SPMSQ ≥ 5) or absence of moderate-severe cognitive deficit (SPMSQ ≤ 2); the continuous variables were expressed in terms of mean ± standard deviation (SD), while the categorical ones in terms of numbers (n) and percentage prevalence (%). Regarding the association between groups, T test for continuous variables and the Chi square test for categorical variables was performed. The association between variables was carried out by calculating the odds ratio (OR) and confidence intervals (95%CI), using univariate and multivariate logistic analysis, to correct the association due to various confounding factors. Two logistic analysis models were therefore created: the model corrected for age and sex and the fully adjusted model, corrected for the significative confounding factors in the preliminary descriptive analysis. A second logistic analysis was performed to investigate the association between oral health and alteration of executive functions. A p value of ≤ 0.05 was considered as significant for all analyses. The data were analyzed using R 4.0 software.

3. Results

Two-hundred eighteen patients met the inclusion criteria and were included in this study (95 males and 123 females, mean aged 75.3 ± 10.1 years): 33 patients with a SPMSQ ≥5 (mean aged 65.8 ± 11.3 years), and 185 with a SPMSQ ≤2 (mean aged 77.0 ± 8.9 years). The study population characteristics are reported in Table 1.

Between-group analysis showed that diagnosis of diabetes (p-value < 0.001) and stroke (p-value = 0.004), sedative drug administration (p-value < 0.001), anticoagulant therapy (p-value < 0.001), and bisphosphonate therapy (p-value < 0.001) were significantly different between groups(see Table 1 for further details).

Regarding the association between oral health and moderate-severe cognitive decline, the predictive values were represented by the diagnosis of stroke (OR = 3.00; 95% CI: 1.09–9.27), sedative drugs administration (OR = 2.46; 95% CI: 1.06–5.78), anticoagulant therapy (OR = 2.61; 95% CI: 1.08–6.17), GOHAI test (OR = 7.06; 95% CI: 2.19–23.54), and poor nutritional status (OR = 2.11; 95% CI: 0.98–5.41) (see Table 2 for further details).

Regarding the association between oral health status and altered executive performance (TMT-B), the predictive values of cognitive deterioration are represented by reduction of the vertical dimension (OR = 1.60; 95% CI: 0.52–4.89) reduction in muscle coordination (OR = 10.10; 95% CI: 2.87–39.80), Newton’s stomatitis (OR = 3.68; 95% CI: 1.14–13.15), reversal clenching (OR = 1.38; 95% Cl: 0.47–3.89), and GOHAI test (OR = 4.83; 95% CI: 1.47–16.52) (see Table 3 for further details).

4. Discussion

The main aim of this study was to evaluate the correlation between the GOHAI and the cognitive impairment and the additional aim was to compare their oral health to those of people without cognitive impairment. Results from the present multicenter cross-sectional study suggested that older people with cognitive decline showed a poor oral health, worse than people with normal cognitive status. Furthermore, the oral status was associated with cognitive decline in our elderly cohort and our findings showed that oral status was associated with impaired executive performance. Our results have demonstrated differences in terms of alteration of Newton’s stomatitis (p-value < 0.001) and oral candidiasis (p-value = 0.004), between elderly people with cognitive decline and healthy elderly.

The aging process of the oral cavity undergoes many physiologic changes, commonly related to the chronic systemic diseases and their associated treatments (inflammatory response, medication, chemotherapy, and radiotherapy) [42–43]. It was demonstrated that age-related changes of the oral mucosa showed a decrease in the elastic fibers and thickening, with disorganization of the collagen bundles in the connective tissue [44]. In the elderly population, an increase in concentration of IgA and a decrease in total protein concentration in saliva appear, with consequent thicker and more ropey saliva [45]. Moreover, elderly people with dementia generally have oral hygiene issues [29,46], and, specifically, they tend to have more prevalent periodontal problems, including gingival bleeding, periodontitis, attachment loss, and xerostomia and oral lesions, such as stomatitis and candidiasis [47–51].

A review on the topic showed that oral health in people with dementia was poor and not related to the subtype of dementia. In contrast, the severity of cognitive decline has been reported to affect the oral health of older adults, with greater plaque and oral disease in those with more severe cognitive decline [22].

During the last decade, authors supported the bidirectional mechanism underpinning the association between oral health and dementia [26–29]. In this context, Saito et al. [27] conducted a 4-year prospective cohort study and showed that subjects with 0–9 teeth were 3 times more likely to develop cognitive impairment than those with ≥10 teeth. Accordingly, the study by Ishimiya et al. [26] showed that tooth loss-related dietary patterns could be associated with a high prevalence of cognitive impairment. Thus, it seems that the oral health of older people with cognitive decline may be related to their cognitive function and overall health.

According to these results, our study demonstrated that oral status was associated with cognitive status. Campos et al. [52] hypothesized that an impaired masticatory system could affect nutritional intake and might lead to reduced cerebral stimulation and blood flow, thus favoring the development and/or worsening of dementia. On the other hand, a systematic review by Pazos et al. [49] found that the association between periodontal disease and dementia remained inconclusive. However, a plausible mechanism of periodontal disease that is conducive to the development of Alzheimer’s disease involves pathogens from the oral cavity entering the bloodstream and crossing the blood-brain barrier more readily as the person ages. This inflammatory mechanism can increase cerebral inflammation, a possible cause of cognitive decline [53]. In fact, the chronic inflammation operates similarly to the vicious cycle that leads to neurodegeneration [54].

Moreover, our findings indicated poor nutritional status among older people with cognitive decline. It is well known that movement disability has a high prevalence in the elderly population, either healthy or with chronic disease, and the decline of nutritional status is an expected condition in the elderly, especially in hospitalized elderly subjects. This condition itself might contribute to the onset and worsening of malnutrition [55–56]. Nonetheless, malnutrition and physical disability are urgent problems in aging and super-aging societies, and the two phenomena are closely linked among the elderly; both conditions share common underlying pathogenesis, including physiological changes associated with aging and burdens imposed by disease or injury [55–56].

This study has some limitations: firstly, the cross-sectional design of the study prevents a causal relationship from being established between oral health status and cognitive decline; secondly, lack of data on different causes of cognitive decline, a parameter that might be useful to better cluster our cohort; thirdly, absence of data on the level of disability and on the nutritional assessment in our cohort [dietary intake, amino acid supplementation, use of supplements, etc.]; lastly, the absence of power analysis to make more robust the results of our study.

The results of the present study might lead physicians and several health care professionals to the tailored management of oral care in older adults based on objective data; in particular, a precise clusterization may lead to better identify patients at high risk, guiding the prescription of preventive.

5. Conclusions

In conclusion, the results of our study have demonstrated that oral status seemed to be associated with poor cognitive performance in elderly people. The results of the present study might lead physicians and several health care professionals to the tailored management of oral care in older adults based on objective data; in particular, a precise clusterization may lead to better identification of patients at high risk, guiding the prescription of preventive strategies to reduce the onset of oral diseases and optimizing resources.

Consent for publication

Written consent to publication was obtained from each participant, who were informed that their sensitive data would not be divulged.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Competing interest

Authors declare no conflict of interest and that they did not receive support from any organization for the submitted work. All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Acknowledgements

None.

References

1. Mahncke HW, Connor BB, Appelman J, et al. Memory enhancement in healthy older adults using a brain plasticity-based training program: a randomized, controlled study. Proc Natl Acad Sci U S A. 2006;103(33):12523–12528. doi:10.1073/pnas.0605194103 https://doi.org/10.1073/pnas.0605194103
2. Novoa AM, Juárez O, Nebot M. Efectividad de las intervenciones cognitivas en la prevención del deterioro cognitivo en personas mayores sanas (Review of the effectiveness of cognitive interventions in preventing cognitive deterioration in healthy elderly individuals). Gac Sanit. 2008;22(5):474–482. doi:10.1157/13126930 https://doi.org/10.1157/13126930
3. Gómez-Soria I, Iguacel I, Aguilar-Latorre A, et al. Cognitive stimulation and cognitive results in older adults: A systematic review and meta-analysis. Arch Gerontol Geriatr. 2023;104:104807. doi:10.1016/j.archger.2022.104807 https://doi.org/10.1016/j.archger.2022.104807
4. Bianconcini S, Cagnone S. Dynamic latent variable models for the analysis of cognitive abilities in the elderly population. Stat Med. 2021;40(20):4410–4429. doi:10.1002/sim.9038 https://doi.org/10.1002/sim.9038
5. de Sire A, Ferrillo M, Gennari A, Cisari C, Pasqua S, Foglio Bonda PL, Invernizzi M, Migliario M. Bone health, vitamin D status and oral hygiene screening in breast cancer women before starting osteoporosis treatment: a cross-sectional study. J Biol Regul Homeost Agents. 2021 Jan-Feb;35(1):397–402. doi:10.23812/20-686-L. PMID: 33538147. https://doi.org/10.23812/20-686-L
6. Millán-Calenti JC, Tubío J, Pita-Fernández S, Rochette S, Lorenzo T, Maseda A. Cognitive impairment as predictor of functional dependence in an elderly sample. Arch Gerontol Geriatr. 2012;54(1):197–201. doi:10.1016/j.archger.2011.02.010 https://doi.org/10.1016/j.archger.2011.02.010
7. Burke SN, Barnes CA. Neural plasticity in the ageing brain. Nat Rev Neurosci. 2006;7(1):30–40. doi:10.1038/nrn1809 https://doi.org/10.1038/nrn1809
8. Kaido M, Fukui M, Kawashima M, Negishi K, Tsubota K. Relationship between visual function and cognitive function in older people: A cross-sectional observational study. PLoS One. 2020;15(5):e0233381. Published 2020 May 19. doi:10.1371/journal.pone.0233381 https://doi.org/10.1371/journal.pone.0233381
9. Langa KM, Levine DA. The diagnosis and management of mild cognitive impairment: a clinical review. JAMA. 2014;312(23):2551–2561. doi:10.1001/jama.2014.13806 https://doi.org/10.1001/jama.2014.13806
10. McArdle J, Smith J, Willis RJ. Cognition and economic outcomes in the health and retirement study. In: D Wise, ed. Explorations in the Economics of Aging. Cambridge, MA: National Bureau of Economic Research; 2011. doi:10.2139/ssrn.1434603. https://doi.org/10.2139/ssrn.1434603
11. Ferrillo M, Migliario M, Marotta N, Lippi L, Antonelli A, Calafiore D, Ammendolia V, Fortunato L, Renò F, Giudice A, Invernizzi M, de Sire A. Oral Health in Breast Cancer Women with Vitamin D Deficiency: A Machine Learning Study. J Clin Med. 2022 Aug 9;11(16):4662. doi:10.3390/jcm11164662. https://doi.org/10.3390/jcm11164662
12. de Sire A, Ferrillo M, Lippi L, et al. Sarcopenic Dysphagia, Malnutrition, and Oral Frailty in Elderly: A Comprehensive Review. Nutrients. 2022;14(5):982. Published 2022 Feb 25. doi:10.3390/nu14050982 https://doi.org/10.3390/nu14050982
13. Henry RG, Smith BJ. Managing older patients who have neurologic disease: Alzheimer disease and cerebrovascular accident. Dent Clin North Am. 2009;53(2):269–ix. doi:10.1016/j.cden.2008.12.011 https://doi.org/10.1016/j.cden.2008.12.011
14. Chávez EM, Wong LM, Subar P, Young DA, Wong A. Dental Care for Geriatric and Special Needs Populations. Dent Clin North Am. 2018;62(2):245–267. doi:10.1016/j.cden.2017.11.005 https://doi.org/10.1016/j.cden.2017.11.005
15. Huang ST, Chiou CC, Liu HY. Risk factors of aspiration pneumonia related to improper oral hygiene behavior in community dysphagia persons with nasogastric tube feeding. J Dent Sci. 2017;12(4):375–381. doi:10.1016/j.jds.2017.06.001 https://doi.org/10.1016/j.jds.2017.06.001
16. Liu F, Song S, Ye X, Huang S, He J, Wang G, Hu X. Oral health-related multiple outcomes of holistic health in elderly individuals: An umbrella review of systematic reviews and meta-analyses. Front Public Health. 2022 Oct 27;10:1021104. doi:10.3389/fpubh.2022.1021104. https://doi.org/10.3389/fpubh.2022.1021104
17. Ferrillo M, Migliario M, Agostini F, et al. Oral health-related quality of life in older people: an umbrella review of systematic reviews from a multidisciplinary rehabilitation point of view. Clin Ter. 2024;175(1):73–82. doi:10.7417/CT.2024.5036
18. Gonsalves WC, Wrightson AS, Henry RG. Common oral conditions in older persons. Am Fam Physician. 2008 Oct 1;78(7):845–52. PMID: 18841733.
19. Petersen PE, Yamamoto T. Improving the oral health of older people: the approach of the WHO Global Oral Health Programme. Community Dent Oral Epidemiol. 2005;33(2):81–92. doi:10.1111/j.1600-0528.2004.00219.x https://doi.org/10.1111/j.1600-0528.2004.00219.x
20. Akbiyik Az ZA, Majidov S, Saruhanoglu A, Ak G. Oral mucosal lesions and oral health-related quality of life (GOHAI) in nursing home residents and community-dwelling older adults in Türkiye: a comparative cross-sectional study. BMC Geriatr. 2026 Apr 14;26(1):730. doi:10.1186/s12877-026-07497-5. https://doi.org/10.1186/s12877-026-07497-5
21. Turner MD, Ship JA. Dry mouth and its effects on the oral health of elderly people. J Am Dent Assoc. 2007;138 Suppl:15S-20S. doi:10.14219/jada.archive.2007.0358 https://doi.org/10.14219/jada.archive.2007.0358
22. Delwel S, Binnekade TT, Perez RSGM, Hertogh CMPM, Scherder EJA, Lobbezoo F. Oral hygiene and oral health in older people with dementia: a comprehensive review with focus on oral soft tissues. Clin Oral Investig. 2018;22(1):93–108. doi:10.1007/s00784-017-2264-2 https://doi.org/10.1007/s00784-017-2264-2
23. Tôrres LH, Tellez M, Hilgert JB, Hugo FN, de Sousa MD, Ismail AI. Frailty, Frailty Components, and Oral Health: A Systematic Review. J Am Geriatr Soc. 2015;63(12):2555–2562. doi:10.1111/jgs.13826 https://doi.org/10.1111/jgs.13826
24. Borg-Bartolo R, Roccuzzo A, Gambetta-Tessini K, Schimmel M, Molinero-Mourelle P, Sabatini G, Ferrillo M, Esteves-Oliveira M, Giacaman RA, Tennert C, Campus G. Association between oral health-related quality of life and structural determinants of health among elderly populations. a systematic review and meta-analysis. Int J Equity Health. 2025 Jul 1;24(1):189. doi:10.1186/s12939-025-02557-5. https://doi.org/10.1186/s12939-025-02557-5
25. Zhu Y, Hollis JH. Tooth loss and its association with dietary intake and diet quality in American adults. J Dent. 2014;42(11):1428–1435. doi:10.1016/j.jdent.2014.08.012 https://doi.org/10.1016/j.jdent.2014.08.012
26. Ishimiya M, Nakamura H, Kobayashi Y, et al. Tooth loss-related dietary patterns and cognitive impairment in an elderly Japanese population: The Nakajima study. PLoS One. 2018;13(3):e0194504. Published 2018 Mar 15. doi:10.1371/journal.pone.0194504. https://doi.org/10.1371/journal.pone.0194504
27. Saito S, Ohi T, Murakami T, et al. Association between tooth loss and cognitive impairment in community-dwelling older Japanese adults: a 4-year prospective cohort study from the Ohasama study. BMC Oral Health. 2018;18(1):142. doi:10.1186/s12903-018-0602-7. https://doi.org/10.1186/s12903-018-0602-7
28. Wu B, Fillenbaum GG, Plassman BL, Guo L. Association Between Oral Health and Cognitive Status: A Systematic Review. J Am Geriatr Soc. 2016;64(4):739–751. doi:10.1111/jgs.14036 https://doi.org/10.1111/jgs.14036
29. Qadir BH, Mahmood MK, Amin YMM, Kurda HA, Rasheed TA, Noori AH, Noori ZF, Abdulghafor MA, Fadhil HNM, Fatih MT, Tardivo D, Tassery H, Lan R. Periodontitis and Tooth Loss Are Associated With Higher Risks of Cognitive Disorders: A Systematic Umbrella Meta-Analysis. Clin Exp Dent Res. 2025 Dec;11(6):e70240. doi:10.1002/cre2.70240. https://doi.org/10.1002/cre2.70240
30. Tonsekar PP, Jiang SS, Yue G. Periodontal disease, tooth loss and dementia: Is there a link? A systematic review. Gerodontology. 2017;34(2):151–163. doi:10.1111/ger.12261. https://doi.org/10.1111/ger.12261
31. Sparks Stein P, Steffen MJ, Smith C, et al. Serum antibodies to periodontal pathogens are a risk factor for Alzheimer’s disease. Alzheimers Dement. 2012;8(3):196–203. doi:10.1016/j.jalz.2011.04.006 https://doi.org/10.1016/j.jalz.2011.04.006
32. Cuschieri S. The STROBE guidelines. Saudi J Anaesth. 2019;13(Suppl 1):S31–S34. doi:10.4103/sja.SJA_543_18 https://doi.org/10.4103/sja.SJA_543_18
33. World Medical Association. World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. JAMA. 2013;310(20):2191–2194. doi:10.1001/jama.2013.281053 https://doi.org/10.1001/jama.2013.281053
34. Liu X, Xia X, Hu F, et al. The mediation role of sleep quality in the relationship between cognitive decline and depression. BMC Geriatr. 2022;22(1):178. Published 2022 Mar 3. doi:10.1186/s12877-022-02855-5 https://doi.org/10.1186/s12877-022-02855-5
35. Pfeiffer E. A short portable mental status questionnaire for the assessment of organic brain deficit in elderly patients. J Am Geriatr Soc. 1975;23(10):433–441. doi:10.1111/j.1532-5415.1975.tb00927.x https://doi.org/10.1111/j.1532-5415.1975.tb00927.x
36. Sánchez-García S, Heredia-Ponce E, Juárez-Cedillo T, et al. Psychometric properties of the General Oral Health Assessment Index (GO-HAI) and dental status of an elderly Mexican population. J Public Health Dent. 2010;70(4):300–307. doi:10.1111/j.1752-7325.2010.00187.x https://doi.org/10.1111/j.1752-7325.2010.00187.x
37. Atchison KA, Dolan TA. Development of the Geriatric Oral Health Assessment Index. J Dent Educ. 1990 Nov;54(11):680–7. PMID: 2229624. https://doi.org/10.1002/j.0022-0337.1990.54.11.tb02481.x
38. Braden BJ, Maklebust J. Preventing pressure ulcers with the Braden scale: an update on this easy-to-use tool that assesses a patient’s risk. Am J Nurs. 2005;105(6):70–72. doi:10.1097/00000446-200506000-00031 https://doi.org/10.1097/00000446-200506000-00031
39. Giovannoni L, Longobucco Y, Iovino P, et al. Complementing Braden scale for pressure ulcer risk with clinical and demographic-related factors in a large cohort of hospitalized Italian patients. J Tissue Viability. 2024;33(2):243–247. doi:10.1016/j.jtv.2024.03.005 https://doi.org/10.1016/j.jtv.2024.03.005
40. REITAN RM. The relation of the trail-making test to organic brain damage. J Consult Psychol. 1955;19(5):393–394. doi:10.1037/h0044509 https://doi.org/10.1037/h0044509
41. Papandonatos GD, Ott BR, Davis JD, Barco PP, Carr DB. Clinical Utility of the Trail-Making Test as a Predictor of Driving Performance in Older Adults. J Am Geriatr Soc. 2015;63(11):2358–2364. doi:10.1111/jgs.13776 https://doi.org/10.1111/jgs.13776
42. Pretty IA, Ellwood RP, Lo EC, et al. The Seattle Care Pathway for securing oral health in older patients. Gerodontology. 2014;31 Suppl 1:77–87. doi:10.1111/ger.12098 https://doi.org/10.1111/ger.12098
43. Thompson LA, Chen H. Physiology of Aging of Older Adults: Systemic and Oral Health Considerations-2021 Update. Dent Clin North Am. 2021;65(2):275–284. doi:10.1016/j.cden.2020.11.002 https://doi.org/10.1016/j.cden.2020.11.002
44. Friedman PK, Kaufman LB, Karpas SL. Oral health disparity in older adults: dental decay and tooth loss. Dent Clin North Am. 2014;58(4):757-770. doi:10.1016/j.cden.2014.06.004 https://doi.org/10.1016/j.cden.2014.06.004
45. Xie Y, Chen S, Sheng L, Sun Y, Liu S. A New Landscape of Human Dental Aging: Causes, Consequences, and Intervention Avenues. Aging Dis. 2023;14(4):1123–1144. Published 2023 Aug 1. doi:10.14336/AD.2022.1224 https://doi.org/10.14336/AD.2022.1224
46. Ming Y, Hsu SW, Yen YY, Lan SJ. Association of oral health-related quality of life and Alzheimer disease: A systematic review. J Prosthet Dent. 2020;124(2):168–175. doi:10.1016/j.prosdent.2019.08.015 https://doi.org/10.1016/j.prosdent.2019.08.015
47. Robinson PG, Deacon SA, Deery C, et al. Manual versus powered toothbrushing for oral health. Cochrane Database Syst Rev. 2005;(2):CD002281. Published 2005 Apr 18. doi:10.1002/14651858.CD002281.pub2 https://doi.org/10.1002/14651858.CD002281.pub2
48. Gao SS, Chu CH, Young FYF. Oral Health and Care for Elderly People with Alzheimer’s Disease. Int J Environ Res Public Health. 2020;17(16):5713. Published 2020 Aug 7. doi:10.3390/ijerph17165713 https://doi.org/10.3390/ijerph17165713
49. Pazos P, Leira Y, Domínguez C, Pías-Peleteiro JM, Blanco J, Aldrey JM. Association between periodontal disease and dementia: A literature review. Asociación entre enfermedad periodontal y demencia. Revisión de la bibliografía. Neurologia (Engl Ed). 2018;33(9):602–613. doi:10.1016/j.nrl.2016.07.013. https://doi.org/10.1016/j.nrl.2016.07.013
50. Nadim R, Tang J, Dilmohamed A, et al. Influence of periodontal disease on risk of dementia: a systematic literature review and a meta-analysis. Eur J Epidemiol. 2020;35(9):821–833. doi:10.1007/s10654-020-00648-x. https://doi.org/10.1007/s10654-020-00648-x
51. Kusdhany LS, Rahardjo TB, Agustin D, Masulili C, Lelyati S, Hogervorst E. Oral hygiene status and cognitive function in Indonesian elderly. Int J Clin Prev Dent. 2015;11:261–264. doi:10.15236/ijcpd.2015.11.4.261. https://doi.org/10.15236/ijcpd.2015.11.4.261
52. Campos CH, Ribeiro GR, Rodrigues Garcia RCM. Mastication and oral health-related quality of life in removable denture wearers with Alzheimer’s disease. J Prosthet Dent. 2018;119(5):764–768. doi:10.1016/j.prosdent.2017.07.010. https://doi.org/10.1016/j.prosdent.2017.07.010
53. Scannapieco FA, Shay K. Oral health disparities in older adults: oral bacteria, inflammation, and aspiration pneumonia. Dent Clin North Am. 2014;58(4):771–782. doi:10.1016/j.cden.2014.06.005. https://doi.org/10.1016/j.cden.2014.06.005
54. Cerajewska TL, Davies M, West NX. Periodontitis: a potential risk factor for Alzheimer’s disease. Br Dent J. 2015;218(1):29–34. doi:10.1038/sj.bdj.2014.1137. https://doi.org/10.1038/sj.bdj.2014.1137
55. Nishioka S, Wakabayashi H. Interaction between malnutrition and physical disability in older adults: is there a malnutrition-disability cycle?. Nutr Rev. 2023;81(2):191–205. doi:10.1093/nutrit/nuac047. https://doi.org/10.1093/nutrit/nuac047
56. de Sire A, Baricich A, Ferrillo M, Migliario M, Cisari C, Invernizzi M. Buccal hemineglect: is it useful to evaluate the differences between the two halves of the oral cavity for the multidisciplinary rehabilitative management of right brain stroke survivors? A cross-sectional study. Top Stroke Rehabil. 2020;27(3):208–214. doi:10.1080/10749357.2019.1673592. https://doi.org/10.1080/10749357.2019.1673592

Table 1. Demographic and clinical characteristics of patients included in the study [n = 218] and after stratification according to the Short Portable Mental Status Questionnaire.

	All [n = 218]	Moderate-severe cognitive decline [n = 33]	No cognitive decline [n = 185]	P-value
Age [years]	75.3 ± 10.1	65.8 ± 11.3	77.0 ± 8.9	<0.001
Sex [n/%]	95 [43.6]	19 [57.6]	76 [41.1]	0.120
Diabetes [n,%]	162 [74.3]	18 [54.5]	144 [77.8]	0.009
Stroke [n,%]	93 [42.7]	6 [18.2]	87 [47.0]	0.004
Number of drugs [n]	5.3 ± 1.2	4.8 ± 1.7	5.3 ± 1.1	0.110
Sedative [n,%]	144 [66.1]	13 [39.4]	131 [70.8]	<0.001
Anticoagulants [n,%]	169 [77.5]	17 [51.5]	152 [82.2]	<0.001
Bisphosphonates [n,%]	106 [48.6]	6 [18.2]	100 [54.1]	<0.001
GOHAI < 51 [n,%]	158 [72.5]	8 [24.2]	150 [81.1]	<0.001
Poor nutritional status [n,%]	166 [76.1]	12 [36.4]	154 [83.2]	<0.001

Continuous variables are expressed as means/standard deviations; categorical variables are expressed as counts/percentages. Abbreviation: SPMSQ = Short Portable Mental Status Questionnaire; GOHAI = General Oral Health Assessment Index.

Table 2. Association between oral health and moderate-severe cognitive decline..

	Age and sex-adjusted OR [95% CI]	Fully adjusted OR [95% CI]^*
Age	1.10 [1.06–1.16]	-
Sex	0.62 [0.27–1.41]	-
Diabetes	1.16 [0.43–2.90]	-
Stroke	3.00 [1.09–9.27]	-
Sedative	2.46 [1.06–5.78]	-
Anticoagulants	2.61 [1.08–6.17]	-
GOHAI <51	7.06 [2.19–23.54]	4.83 [1.47–16.52]
Poor nutritional status	2.11 [0.98–5.41]	-

^*Corrected for age, sex, stroke, sedative, anticoagulants, poor nutrition. Abbreviation: OR = Odds Ratio; GOHAI = General Oral Health Assessment Index.

Table 3. Association between oral health status and altered executive performance.

Age and sex adjusted OR [95%CI]	Fully adjusted OR [95% CI]^*
Age	-
Sex	-
Reduction of vertical dimension	1.60 [0.51–4.89]
Reduction of muscle coordination	10.10 [2.87–39.80]
Integrity of mucosae	-
Newton’s stomatitis	3.68 [1.14–13.15]
Oral candidiasis	-
Reversal clenching	1.38 [0.47–3.89]
GOHAI <51	4.83 [1.47–16.52]
Diabetes	-
Stroke	-
Sedative	-
Anticoagulants	-
Poor nutrition	-

^*Corrected for age, sex, stroke, sedative, anticoagulants, poor nutrition. Abbreviation: OR = Odds Ratio; GOHAI = General Oral Health Assessment Index.