Age and sex differences in the association of dental visits with inadequate oral health and multimorbidity: Findings from the Canadian Longitudinal Study on Aging (CLSA)

Abstract

Background

Dental attendance is important for the prevention, diagnosis, and treatment of oral diseases. In this study, we aimed to assess the extent of the association between dental visits, inadequate oral health, and multimorbidity (MM), and whether this association differs by age and sex.

Methods

We conducted a cross-sectional analysis of the first follow-up wave (2018) of the Canadian Longitudinal Study on Aging (CLSA). Poor self-reported oral health (SROH), oral health problems, and edentulism were used to indicate inadequate oral health. MM was defined as having 2 or more chronic conditions out of cancer, cardiovascular diseases, chronic respiratory diseases, diabetes, and mental illnesses. Dental visiting was determined as the number of visits to a dental professional within the past 12 months. Covariates included socioeconomic, behavioural factors, and the availability of dental insurance. We constructed multivariable Poisson and logistic regression models with interactions terms and estimated the relative excess risk due to interaction prevalence ratio (RERIPR) to assess the effect measure modification of age and sex on the associations of interest. We conducted sensitivity analyses and estimated E-values for unmeasured confounding.

Results

In this sample (n = 44,815), dental visiting was inversely associated with inadequate oral health and MM in adjusted models, reducing the odds/prevalence of poor SROH (OR 0.41, 95% CI 0.34, 0.51), oral health problems (PR 0.89, 95% CI 0.79, 0.94), edentulism (OR 0.10, 95% CI 0.06, 0.15), and MM (PR 0.86, 95% CI 0.79, 0.92). These associations were stronger in older age and females.

Conclusion

Dental visiting may contribute to better oral health and reduced chronic diseases in the middle-aged and older population. Our findings suggest the need for age and sex-specific targeted interventions to optimize oral and overall health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-024-20412-0.

Introduction

Dental attendance is important for the prevention, diagnosis and treatment of oral diseases [1]. Individuals with better dental visiting behaviours have been shown to be less likely to exhibit acute symptoms of oral diseases, have better oral health-related quality of life and require less emergency treatment than those who do not visit a dental professional as often [2]. Conversely, those with sub-optimal dental attendance are often found to have fewer teeth, more dental caries, and worse periodontal health [3, 4]. By extension, such inadequate oral health may lead to increased self-consciousness about dental appearance, thereby affecting self-esteem and social interactions [5].

Although the strength of the evidence remains controversial, dental visits and subsequent oral health care have been suggested to potentially reduce the risk of chronic conditions that are linked to oral diseases such as diabetes, respiratory, and cardiovascular diseases [6]. Dental visits can also contribute to reducing the risk of chronic conditions by motivating positive health behaviours such as smoking cessation, reducing alcohol consumption, and moderating sugar intake [7], which are strongly linked to both oral and systemic health conditions [8]. As described by Sheiham and Watt, the common risk factor approach suggests that there are broader structural and behavioural determinants of health that are shared between oral diseases and other chronic conditions, thereby emphasizing the necessity of understanding how these factors may simultaneously contribute to both groups of disease with an ultimate goal of informing policies on chronic disease prevention [8]. Examining the extent to which dental visiting may enhance oral health and possibly reduce the cumulative chronic disease burden, or MM, is therefore important for understanding the broader impacts of dental care on overall health as well as informing oral health policies. From a Canadian perspective, this is particularly relevant for emerging oral health policies on access to dental care such the Canadian Dental Care Plan (CDCP). This new federal initiative aims to enhance access to dental care for families and older individuals facing financial barriers. Thus, investigating the possible contribution of dental visits to oral and non-oral health concurrently can help inform the CDCP and similar initiatives on the possible impacts of dental care that may extend systemically beyond the mouth [9].

Meanwhile, several factors determine dental visiting including socioeconomic status and access to dental care factors such the availability of dental insurance [10, 11]. Of particular importance, is recognizing the role of non-modifiable, yet actionable, sociodemographic characteristics such as age and sex in how dental visiting contributes to oral and overall health to enhance targeted approaches to oral health policies [12]. The aging process increases the vulnerability to several health conditions [13, 14]. For example, aging has been linked to impaired salivary gland function, xerostomia, changes in salivary compositions and an overall increased risk for dental caries, periodontal disease, oral cancer, poor nutrition, tooth loss and frailty [15, 16]. Other age-related factors physiological and social changes can impact patterns of dental visits such as limitations in movement, social interactions, and the potential loss of dental insurance post-retirement leading to affordability concerns, all of which may underlie a greater need for dental visiting in older age [17]. A recent study from the United Kingdom showed that individuals aged 61 years and older living with multiple chronic conditions, also known as multimorbidity (MM), were more likely to attend the dentist than those without multiple chronic conditions. The study suggested that a higher attendance rate may reflect a greater need for dental care among those with an increased burden of chronic disease, regardless of whether the visits were for emergency appointments or regular check-ups [18]. In Canada, recent data suggest that only 43.5% of Canadians aged 65 and over visited a dental professional in 2018, compared to 74.5% of the general population [19]. Despite such findings and plausible pathways linking dental visiting to oral health and possibly chronic conditions, less is known on the extent to which dental visits are associated with oral health and other chronic health conditions and MM.

Meanwhile, an individual’s sex is also an important determinant of health. For example, females are known to be more prone to oral health conditions and to experience varying disease trajectories than males, such as oral health changes during pregnancy and menopause often due to hormonal fluctuations and related immune responses [20, 21]. In addition, socioeconomic factors, cultural norms and healthcare utilization patterns may interact differentially with age and sex [22]. Females may exhibit more positive attitudes about dental visits, greater oral health literacy and demonstrate better health behaviours than males, who on the contrary, demonstrate worse oral hygiene behaviours, greater tobacco use, and heavier alcohol consumption [23]. However, in Canada, studies suggest that females are more likely than males to have untreated dental decay, missing teeth and oral pain than males, particularly those from lower income groups [24]. Meanwhile, a few studies have emphasized sex-differences in the development of several chronic conditions and their risk factors including vulnerability to chronic stress and response to drug treatments, for example [25].

Given the above, we sought to assess the extent of the association between dental visits with inadequate oral health and MM and determine whether any association is modified by age and sex in Canadian middle-aged and older adults. We hypothesized that the prevalence of inadequate oral health and MM will be lower among individuals who visited a dental professional in the past year, with stronger associations observed in older individuals and females.

Materials and methods

Data source and study design

In this cross-sectional study, we sourced data from the Canadian Longitudinal Study on Aging (CLSA), a large, national, population-based cohort that aims to understand the biological, medical, psychological, social, lifestyle, and economic factors that influence the aging process. CLSA includes a total of 51,338 women and men aged 45 to 85 years. To be eligible for the CLSA study, participants must reside in one of the 10 provinces in Canada, be capable of completing the questionnaires in either English or French, have the cognitive ability to participate independently from all Canadian provinces. The study excluded Indigenous people living on First Nations’ reserves, institutionalized individuals, and full-time members of the Canadian military. All participants were community-dwelling at the time of enrollment, answered questions either through a computer-assisted telephone survey or an in-person home interview on their demographic, physical, psychosocial, and economic status, and health service use. The recruitment process involved contacting a random selection of eligible households. If an eligible individual was identified within the household, they were requested to share their details with the CLSA for future contact regarding recruitment [26]. For our study, we used data from the first-follow up cycle (2015 to 2018) from both CLSA cohorts: comprehensive (in-person interviews), and tracking (telephone interviews). The proportion of missing data throughout the CLSA dataset was low (< 5%), which was managed using listwise deletion due to its minimal proportion [26]. Approval to access the data for the purposes of this project was obtained from CLSA (Application Number: 2203002) and our study was approved by Western University Research Ethics Board (Project#: 120760).

Study variables

Dental visiting was defined using the CLSA question: ‘When did you last visit a dental professional?’ The response options were ‘in the last 12 months’, ‘in the last 5 years’, ‘in the last 10 years’, ‘more than 10 years ago’, and ‘never’. We dichotomized this variable into those who had visited a dental professional within the last 12 months and those who have last visited a dental professional more than 12 months ago at the time of data collection. To enhance the comparability of our results and reduce issues of recall bias, we used a cut-off point of 12 months based on previous studies on dental care utilization [27–29], while also considering studies that used a representative sample of the Canadian population [30].

Inadequate oral health was defined using three oral health indicators: (i) self-reported oral health (SROH), (ii) other oral health problems and (iii) edentulism. SROH was defined by the question ‘In general, would you say that the health of your mouth is excellent, very good, good, fair, or poor?’. In agreement with the literature in dichotomizing this standardized measure [31, 32], this was dichotomized as good (for responses including ‘excellent’, ‘very good’, and ‘good’) and poor (for responses including ‘fair’ or ‘poor’) SROH. Oral health problems were defined as having at least one of the three conditions: oral pain (reporting at least one of the following: presence of toothache, swelling in the mouth, burning mouth, jaw muscles sores, jaw joints painful, tooth-decay, sore gums around natural teeth, or denture-related sores), oral inflammation (defined by the question ‘In the past 12 months have you experienced that your gums around natural teeth bleed?’), and difficulty when eating due to oral health problems (defined by the question ‘In the past 12 months, how often have you avoided eating particular foods because of problems with your mouth, teeth or dentures?). Edentulism was defined by answering ‘no’ to the question ‘Do you have one or more of your original teeth?’.

Multimorbidity (MM)

Globally, there is no consensus on the definition of MM. Here, MM was defined according to the latest definition of the Public Health Agency of Canada as the co-existence of two or more chronic conditions [33] out of cancer, cardiovascular diseases (heart disease, stroke), chronic respiratory diseases (asthma, chronic obstructive pulmonary diseases), diabetes, and mental illnesses (mood, anxiety disorders). We used the cut-off point of the co-occurrence of at least 2 of these 5 chronic conditions to dichotomize this variable into MM and no MM [34].

Covariates

Age was categorized into four age groups: 45–54, 55–64, 65–74, and 75 years of age and older. Sex was categorized as males and females, as reported in CLSA. Race/ethnicity was categorized as white and non-white as there was only a small number of respondents in the other racial/ethnic groups to allow for meaningful interpretation around racial/ethnic categorizations. Other covariates included total household income per annum and level of education, smoking status, alcohol consumption, medication intake, the availability of dental insurance, and toothbrushing frequency.

Statistical analysis

To address the complexity of the survey design, we used trimmed and analytic weights [35]. Our statistical analyses were carried out in sequential steps. First, we applied weighted descriptive statistics and calculated weighted percentages for all categorical variables. Next, Poisson robust multivariable regression was employed to estimate prevalence ratios (PR) and 95% confidence intervals (CI) of the association between dental visits, inadequate oral health and MM, adjusted for the aforementioned covariates. We opted for the Poisson robust regression to overcome the limitations of binomial logistic regressions in overestimating the magnitude of the effect in cross-sectional studies [36]. While for edentulism, with a prevalence < 10% (typically considered as a low prevalence in the sample), we opted to use logistic regression to estimate odds ratios to avoid overestimation. In addition, we conducted subgroup analyses to assess the effect measure modification by age and sex on both the multiplicative and additive scales. For this, we constructed interactions terms by age groups, and by sex to estimate their effect modification of the relationship between dental visits and inadequate oral health and MM. We also estimated the relative excess risk due to interaction for prevalence ratio (RERIPR). Finally, we conducted a sensitivity analysis for unmeasured confounders by assessing the robustness of our estimates using the E-values for each exposure-outcome association. All analyses were conducted using Stata v18.0 statistical software [37].

Results

Characteristics of the study population

The sample size consisted of 41,815 participants, mostly females (51.3%) and white individuals (94.3%) (Table 1). Most participants fell in the 55–64 years old age group (32.7%), followed by the 65–74 years old age group (29.5%). A smaller group of participants were between 45 and 55 years of age (14%). The majority had post-secondary education, and 89.97% were employed. Most respondents reported being non-smokers (92.1%) and regular drinkers (56.3%). Most respondents also reported having visited a dental professional in the last year (82.2%), with females showing slightly higher dental attendance than males (83.5% and 81.9% respectively). Almost half of the participants had no dental insurance coverage (42.1%), with females being more affected than males. About 12% of respondents reported dental care affordability issues, with females experiencing more cost barriers than males (12.9% and 9.9% respectively). More females experienced edentulism than males (8.8% and 8% respectively). Also, while 89.7% of the participants reported good oral health, more males had poor SROH compared to females (9.8% and 9.1% respectively). Similarly, more males reported experiencing oral health problems (oral pain, oral inflammation, and difficulty eating due to oral health problems) than females (62.4% and 61.5% respectively). The weighted prevalence of MM was 23.5%, with females being more affected than males.

Table 1.

Weighted descriptive statistics of characteristics of study participants (n = 44,815), CLSA, first follow-up wave, 2018

Variable		All % (n = 44,815)	Males % (n = 21,760)	Females % (n = 23,055)
Age group	45 to 54y	14	13.6	14.4
	55 to 64y	32.7	31.3	34
	65 to 74y	29.5	30.6	28.4
	75 + y	23.7	24.3	23
Race/Ethnicity	White	94.3	94.2	94.4
	Non-white	5.6	5.7	5.5
SROH	Poor	10.2	9.8	9.1
	Good	89.7	90.1	90.8
Oral health problems (oral pain, oral inflammation, difficulty when eating)	Yes	61.3	62.4	61.5
	No	38.7	37.6	38.5
Edentulism	Yes	8.4	8	8.8
	No	91.5	91.9	91.1
MM	Yes	23.5	23	23.9
	No	76.5	76.9	76
Dental visits within the last year	Yes	82.2	81.9	83.5
	No	17.7	18.1	16.4
Level of education	Postsecondary education or higher	89	89.5	89.9
	Less than post-secondary education	10.9	10.4	10
Annual household income level	Low (< $50,000/year)	28.8	27.5	29.7
	Middle ($50,000 to < 100,000/year)	38.1	38.1	38.7
	High (≥ $100,00/year)	33	34.2	31.5
Employment status	Currently working	89.9	89.5	81.5
	Unemployed	10	10.4	18.4
Smoking status	Smoker	7.8	7	8.5
	Non-smoker	92.1	92.9	91.4
Frequency of alcohol consumption	Drinker (at least once a week)	56.3	62.5	49.9
	Rarely drinker (never or less than once a month)	43.6	37.4	50
Medication intake	Yes	18.9	19.3	18.2
	No	81.1	80.7	81.7
Frequency of toothbrushing	Optimal (more than once a day)	84.5	83.2	85.9
	Suboptimal (once a day or less)	15.5	16.2	14.8
Dental insurance status	Insured	57.8	59.9	57.3
	Uninsured	42.1	40	42.6
Cost barriers to dental care	Yes	11.9	9.9	12.9
	No	88	90.1	87.1

MM: multimorbidity. SROH: self-reported oral health

Dental visits inversely associate with inadequate oral health and MM

Dental visits within the last 12 months were inversely and significantly associated with inadequate oral health indicators and MM. Specifically, adjusted models showed that those who had visited a dental professional within the last 12 months had a significantly reduced prevalence or odds of poor SROH (PR 0.41, 95% CI 0.34, 0.51), oral health problems (PR 0.89, 95% CI 0.79, 0.94), edentulism (OR 0.10, 95% CI 0.06, 0.15), and MM (PR 0.86, 95% CI 0.79, 0.92), than those who reported their last dental visit to have occurred more than 12 months ago (Table 2).

Table 2.

Association between dental visits and inadequate oral health indicators and multimorbidity, CLSA, first follow-up wave, 2018

	Model 1	Model 2
Poor SROH (PR, 95% CI)	0.34 (0.30, 0.37)	0.41 (0.34, 0.51)
Oral health problems (PR, 95% CI)	0.70 (0.66, 0.73)	0.89 (0.79, 0.94)
Edentulism (OR, 95% CI)	0.06 (0.05, 0.07)	0.10 (0.06, 0.15)
MM (PR, 95% CI)	0.67 (0.61, 0.73)	0.86 (0.79, 0.92)

Model 1: Crude associations (unadjusted). Model 2: Additionally adjusted for age, sex, race/ethnicity, income level, education level, smoking status, alcohol consumption, toothbrushing frequency, medication intake, availability of dental insurance. CI: confidence interval. MM: multimorbidity. OR: odds ratio. PR: prevalence ratio. SROH: self-reported oral health

Age as an effect modifier of the association between dental visits, inadequate oral health, and MM

The protective association between dental visiting and poor SROH was significant in all age groups, with the highest effect observed in the oldest age group. Specifically, an 91% reduction in the prevalence of poor SROH was observed in those aged 75 years or older who had visited a dental professional over the past year (PR 0.09, 95% CI 0.04, 0.17). This protective association was also observed in the other age groups with the reduction in the prevalence of poor SROH ranging from 67 to 75%, with similar observations with other inadequate oral health indicators including oral health problems and edentulism. While the effect measure modification on the additive scale suggested that age did not contribute to the association between dental visits and poor SROH in adjusted models (RERIPR= -0.05), we found that the magnitude of the effect of dental visits on the reduced the odds of edentulism was higher in the oldest age group, with age contributing to 12% of this association (RERIPR = 0.01). Additionally, while the prevalence of oral health problems was higher in those aged 75 years or older (PR 0.64, 95% CI 0.59, 0.69), age only contributed 1% to this association (RERIPR = 0.01). For MM, the prevalence was higher in those aged 75 years or older (PR 0.36, 95% CI 0.31, 0.41) compared to those in the 45–54 age group (PR 0.64, 95% CI 0.59, 0.70), with age contributing an estimated 10% (RERIPR = 0.07) to the association of dental visits with MM (Table 3).

Table 3.

Effect measure modification of age to the association between dental visiting, inadequate oral health indicators and multimorbidity, CLSA, first follow-up wave, 2018

	Poor SROH PR (95% CI)	Oral health problems PR (95% CI)	Edentulism OR (95% CI)	MM PR (95% CI)
45 to 54y	0.25 (0.20, 0.38)	0.84 (0.72, 0.93)	0.27 (0.20, 0.39)	0.64 (0.59, 0.70)
55 to 64y	0.26 (0.27, 0.35)	0.88 (0.81, 0.94)	0.15 (0.08, 0.24)	0.54 (0.49, 0.59)
65 to 74y	0.33 (0.26, 0.40)	0.87 (0.82, 0.93)	0.17 (0.10, 0.26)	0.40 (0.36, 0.45)
75 + y	0.09 (0.04, 0.17)	0.64 (0.59, 0.69)	0.12 (0.03, 0.19)	0.36 (0.31, 0.41)
RERIPR (AP)	-0.05 (N/A)	0.01 (1%)	0.01 (12%)	0.07 (10%)

All estimates are adjusted for demographic (sex, and race/ethnicity), socioeconomic (income level, and education level), behavioural factors (smoking status, alcohol consumption, and toothbrushing frequency), medication intake, and the availability of dental insurance. AP: attributable proportion. CI: confidence interval. MM: multimorbidity. PR: prevalence ratio. RERIPR: relative excess risk due to interaction for prevalence ratio. SROH: self-reported oral health

Sex as an effect modifier of the association between dental visits, inadequate oral health, and MM

For both sexes, dental visits were inversely associated with a higher prevalence of inadequate oral health and MM. The adjusted estimates revealed that the prevalence of poor SROH was 65% reduced in females who had visited the dental professional in the past 12 months (PR 0.35, 95% CI 0.24, 0.41), while this was estimated to be at a 60% in males (PR 0.40, 95% CI 0.32, 0.57). On an additive scale, an RERIPR of 0.64 suggested that females who visited a dental professional over the last year perceived their oral health as better than males. Similarly, sex modified the association of dental visits with oral health problems and edentulism by 9% (RERIPR = 0.97) and 80% (RERIPR = 0.59), respectively. In adjusted models, the magnitude of the protective association of dental visiting with MM was higher among females (PR 0.70, 95% CI 0.65, 0.76) than males (PR 0.81, 95% CI 0.76, 0.87) (RERIPR = 0.56) (Table 4).

Table 4.

Effect measure modification of sex to the association between dental visiting, inadequate oral health indicators and multimorbidity, CLSA, first follow-up wave, 2018

	Poor SROH OR (95% CI)	Oral health problems PR (95% CI)	Edentulism OR (95% CI)	MM PR (95% CI)
Females	0.35 (0.24, 0.41)	0.75 (0.71, 0.80)	0.07 (0.03, 0.14)	0.70 (0.65, 0.76)
Males	0.40 (0.32, 0.57)	0.94 (0.89, 1.10)	0.15 (0.09, 0.21)	0.81 (0.76, 0.87)
RERIPR (AP)	0.64 (91%)	0.97 (9%)	0.59 (80%)	0.56 (75%)

All estimates are adjusted for demographic (age, and race/ethnicity), socioeconomic (income level, and education level), behavioural factors (smoking status, alcohol consumption, and toothbrushing frequency), medication intake, and the availability of dental insurance. AP: attributable proportion. CI: confidence interval. MM: multimorbidity. PR: prevalence ratio. RERIPR: relative excess risk due to interaction for prevalence ratio. SROH: self-reported oral health

Sensitivity analysis for unmeasured confounding

Given the potential for residual confounding by unmeasured variables, we assessed the robustness of our estimates by calculating the E-values for each exposure-outcome association to assess the robustness of our findings. The E-values for poor SROH, oral health problems, edentulism, and MM were at 0.52, 0.73, 0.29, and 0.56 respectively, for the lower bound of the CI, and 0.59, 0.69, 0.36, and 0.63 respectively, for the upper bound of the CI, suggesting unmeasured confounders that are moderately associated with both the exposure and outcomes. Unmeasured confounding factors that may contribute to explaining our results include the affordability of dental care, reasons for dental visits, dietary habits, medical and dental history, dental anxiety, and polypharmacy. It is worth mentioning that specifically for MM as an outcome we used a cut-off point of 2 or more chronic conditions. When using a cut-off point of 3 or more chronic conditions, the weighted prevalence fell below 8%, resulting in a narrower scope of individuals categorized as multimorbid.

Discussion

In this population-based, cross-sectional study, we used data retrieved from the first follow-up wave of CLSA to assess the association of dental visiting with inadequate oral health and MM in middle-aged and older Canadians while assessing the modifying role of age and sex in these associations. Our adjusted multivariable analyses controlling for measured confounders showed that dental visits within the last year were inversely associated with both inadequate oral health indicators and MM, significantly reducing the prevalence of poor SROH, oral health problems, edentulism, and MM. While these findings remained significant in both females and males, and across the different age groups, females and the oldest age groups showed a greater reduction in prevalence across all outcomes than males and younger age groups, suggesting the importance of considering age and sex-specific interventions to enhance dental visiting and its determinants including access to dental care.

In agreement with previous research, we found that dental visits within the last year were associated with better oral health including various indicators such as SROH, oral pain, bleeding gums, and less tooth loss or edentulism [4, 38, 39]. Interestingly, a study using clinical oral health measures found that regular dental attenders had fewer untreated carious lesions, but not lower caries experience overall or less periodontal disease levels than irregular attenders [40]. Also, our findings suggesting a protective association between dental visits and MM agree with previous studies that proposed a possible role for dental care in mitigating individual chronic conditions. For example, periodontal therapy and preventive dental interventions have been shown to positively associate with optimal HbA1c levels in individuals with diabetes, fewer exacerbations of chronic obstructive pulmonary diseases, and insulin initiation in the case of diabetes [41, 42]. Additionally, dental visits have been suggested to contribute to the management of chronic conditions through the early detection of oral manifestations, and by fostering a trusting relationship with the dental professional, addressing oral health concerns, and creating a supportive environment for health behaviour change [6].

Our results are suggestive that the association of dental visiting with oral health outcomes is significant across age groups and increases in older age. While older individuals are more prone to periodontal diseases, inflammatory conditions, and other oral diseases such as xerostomia, subsequent dental caries and tooth loss [43], enhancing dental visiting may be key to alleviating oral health problems in this age group. Importantly, studies on dental visiting and MM are scarce, with most of these focusing on polypharmacy with no specific age considerations [44, 45]. We found that age contributed to approximately 10% and 9% to the association of dental visiting with edentulism and MM, respectively, suggesting an overall higher need for dental care in this age group. In addition to preventing and treating oral diseases, dental visiting in older age may contribute to better adherence to medication and healthier behaviours, therefore potentially contributing to reduced chronic disease burden and MM. The limited contribution of age to the association between dental visits and inadequate oral health indicators, despite the higher prevalence of oral health problems in the older age group, may be attributed to the healthy user effect, where those with the most need may be less likely to visit the dentist [38, 46].

We also sought to assess the effect modification of sex on the protective association between dental visiting and the health outcomes of interest. While our results suggested that these associations are similar in both sexes, we found the magnitude of this association to be stronger in females than males. Several factors may come to play to explain why females may benefit more from dental visiting than men. Females may be more likely to visit a dental professional and actively engage in healthy behaviours due to a variety of factors, including but not limited to, societal norms and aesthetic reasons [47]. Other factors such as gains in overall life expectancy and health care utilization may also contribute to sex differences in chronic diseases, where females experience a longer duration for the development of multiple co-existing chronic conditions than males [48]. However, it has been consistently shown that there are inequalities in access to dental care and utilization patterns between the sexes which can contribute to differences in oral health and related chronic conditions [49, 50]. This is consistent with our findings which indicated that more females than males are without dental insurance or face dental care affordability issues.

The strengths of our study include the use of the oral health component of the first CLSA follow-up allowing the inclusion of variables associated with inadequate oral health. For example, edentulism reflects an important oral health indicator since its impact transcends oral health status because of its implication on social interactions, psychosocial changes and general health [51]. Also, the use of a nationwide sample of middle-aged and older Canadians enhances the extrapolation of our findings to the population. Moreover, the use of the most recent public health definition of MM as proposed by the Public Health Agency of Canada adds to the comparability of our results to previous work on MM [6, 34, 52]. We also acknowledge several limitations. The cross-sectional study design limits our ability to establish temporal relationships or causality between dental visiting, oral health, and MM, potentially allowing for reverse causation and unaccounted confounding factors. In addition, the extent of the observed associations in our study may be influenced by unmeasured confounding factors. Our results may be subject to the effects of recall and social desirability biases due to self-reported data. The absence of questions pertaining to the reasons for dental visiting may also limit the interpretations of our findings. Individuals who visited the dentist in the last year may inherently engage in healthier behaviours, which could confound the observed associations between dental visits and better oral health indicators, known as the healthy user effect [46]. We operationalized the alcohol consumption variable according to Canada’s Guidance on Alcohol and Health, 2023 which suggests that any amount of alcohol is unsafe [53]. Therefore, even though our derivation of this variable’s categories may vary from what has been used in the previous literature, it conforms to the most recent Canadian guidelines on alcohol consumption. Notably, the health conditions of older participants, including their mobility, independence, cognitive status, and social support were not accounted for in our study or in our operationalization of MM as we followed the PHAC definition. Importantly, we recognize that since the variable ‘oral health problems’ is a complex one, it is possible that most study respondents had experienced at least one of the three conditions included in this variable (i.e. oral pain, oral inflammation, difficulty eating), thereby leading to misclassification and overestimation of the magnitude of the association. To mitigate this, we conducted a sensitivity analysis using alternative operationalizations for this variable including respondents who have experienced two (48.5%) and all three conditions (35.1%). Our sensitivity analyses showed no statistically significant difference in the magnitude of the association between dental visits and oral health problems with the different operationalizations (Supplementary Table 1). Another limitation of this study is the variation in the time frames used in the CLSA for the questions on dental visits and oral health which may have introduced recall bias. Finally, the lack of racial/ethnic diversity in the CLSA respondents’ pool limits the generalizability of our findings [26]. Future research that employs clinically-assessed oral health data with longitudinal analyses and causal inference methods may provide further insights into how dental visiting patterns may be impacted by the non-modifiable sociodemographic determinants of health including age and sex.

Our findings have implications for policy and practice. We underscore the importance of dental visiting in varying demographic groups. Promoting dental visits can enhance oral health among older adults, and this in turn, may mitigate the cumulative effects of chronic diseases and ultimately improve overall health. Similarly, taking into consideration an individual’s sex as a barrier to dental visiting can help in addressing inadequate oral health and the chronic disease burden while recognizing the unique biological, behavioral, and social factors that differentially influence health in males and females [13]. Importantly, policy initiatives should encourage interdisciplinary collaboration between dentists and physicians to integrate oral health into overall healthcare strategies, especially for older adults. With recent Statistics Canada data indicating that inequalities in dental visiting mostly affect Canadians aged 65 years and above [19], new government policies like the CDCP may ease barriers to dental care in this population and provide opportunities for further research that aims to understand the multitude of factors that determine dental visiting.

Conclusion

Dental visiting was associated with better oral health and reduced chronic disease, particularly in older adults and females. Our findings are suggestive of the need for age and sex-specific targeted interventions to optimize oral and overall health.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Author contributions

CRediT authorship statement: Conceptualization: LL, NG, SS; Methodology: LL, NG, KN, SS; Data curation and formal analysis: LL; Validation: NG, KN, SS; Resources: NG; Writing-original draft: LL; Writing-review and editing: NG, SS, KN; Supervision: NG, SS. All authors approved the final manuscript as submitted. Conflict of interest disclosure: The authors have no conflict of interest to declare.

Funding

NG is supported by funding from the Canadian Institutes of Health Research (CIHR), Schulich School of Medicine & Dentistry, Western University and the Lawson Health Research Institute, London, Ontario, Canada. This research was made possible using the data/biospecimens collected by the Canadian Longitudinal Study on Aging (CLSA). Funding for the Canadian Longitudinal Study on Aging (CLSA) is provided by the Government of Canada through the Canadian Institutes of Health Research (CIHR) under grant reference: LSA 94473 and the Canada Foundation for Innovation, as well as the following provinces, Newfoundland, Nova Scotia, Quebec, Ontario, Manitoba, Alberta, and British Columbia. This research has been conducted using the CLSA dataset Comprehensive Baseline version 5.1 and Comprehensive Follow-up 1 version 3.0 under Application Number [2010027]. The CLSA is led by Drs. Parminder Raina, Christina Wolfson, and Susan Kirkland.

Data availability

The data used for the current study were made available by the CLSA to the authors of this manuscript following an application and project proposal submission and review that is required for data access: https://www.clsa-elcv.ca

Declarations

Ethics approval and consent to participate

All participants provided informed consent to participate in the CLSA. All research conducted in preparation for, or as part of, the CLSA abides by the requirements of the Canadian Institutes of Health Research (CIHR) and relevant institutions for ethical conduct and privacy protection in health research. The CLSA participates in an ethical review process at all sites taking part in the study for data collection. Our project to analyze CLSA data was approved on April 26, 2022, by the Western University Health Science Research Ethics Board (HSREB) (project ID number 120760).

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.