Prevalence of self-reported systemic diseases among edentulous patient visiting tertiary care hospital of Nepal

Abstract

Background

Edentulism(partial/complete) is a significant public health concern, impacting masticatory function, nutritional intake, and overall quality of life. Emerging evidence underscores the bidirectional relationship between oral and systemic health, where chronic oral inflammation like dental caries, periodontal diseases, trauma, and tooth loss may contribute to or exacerbation of systemic conditions such as cardiovascular diseases, hypertension, diabetes mellitus and osteoporosis.

Purpose of study

To determine prevalence of systemic diseases among edentulous patients attending dental department of a tertiary hospital in Nepal.

Methods

A descriptive, cross-sectional study was conducted among 384 edentulous patients consented to participate visiting dental department of Patan Academy of Health Sciences (PAHS) from September 2019 to September 2022. Ethical clearance was obtained from Institutional Review Committee, PAHS (Ref: drs1805291179). Sociodemographic data, medical history, current history of medications for self-reported conditions and dental history were collected through face-to-face interviews. A comprehensive intraoral examination was then conducted to record in Performa sheet and verify missing permanent dentition. Data obtained were entered in Epi data version 5 followed by bivariate and multivariable analysis in Statistical Package for Social Sciences (SPSS) version 21.

Results

Among 384 edentulous patients, 35.70% self- reported at least one systemic disease, with hypertension (21.60%) and diabetes (10.70%) were most prevalent. While 87.60% of those with systemic disease were under medication, 12.04% remained untreated and only 8.7% acknowledged a link between systemic disease and tooth loss. Bivariate analysis showed significant associations between systemic disease and age, edentulousness duration, occupation, and cause of tooth loss. However, in multivariable analysis age and edentulousness duration demonstrated inverse association, suggesting possible reverse causality. Periodontitis and trauma were significantly more common cause of tooth loss in individuals with systemic diseases.

Conclusions

Edentulous patients exhibit a high burden of systemic disease, often without full treatment or awareness of systemic links. Regression analysis suggests a complex, potentially bidirectional relationship between edentulism and systemic disease, challenging assumption of linear causality. Surprisingly, people with higher education or professional jobs were not protected from these conditions. These results highlight the need for better awareness, integrated care between dental and medical services.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-025-07066-z.

Background

Edentulism(partial/complete) is a major public health concern, significantly impacting masticatory function, nutritional intake, and overall quality of life. Emerging evidence underscores the bidirectional relationship between oral and systemic health, where chronic oral inflammation like dental caries, periodontal diseases, trauma, and tooth loss may contribute to or exacerbation of systemic conditions such as cardiovascular diseases, diabetes mellitus and osteoporosis. Theoretical frame works including the oral systemic disease model by Seymour et al. and the inflammatory Burden hypothesis, suggest that edentulism serves as a clinical marker of cumulative oral disease burden and systemic inflammation [1, 2].

Edentulism is the loss of at least one permanent tooth (partial edentulism) or loss of all the permanent teeth (complete edentulism) [3, 4]. This is an irreversible condition which can lead to physical impairment. According to World Health Organization (WHO) criteria, completely edentulous people are considered as physically impaired or disabled due to their inability to eat and speak effectively as these are two essential tasks of the life [3, 5]. Complete edentulism remains a significant international public health concern, particularly adults ages 65years and older. Contrary to assumptions that tooth loss is concentrated in developing countries, high income nations like Ireland (43.3%), Malaysia (56.6%), Netherland (65.4%) and Iceland (71.5%) report some of the highest prevalence rates globally. Gender disparities exists but varies in different regions: while women in United States experience edentulism at rates approximately 3% higher than men. Socioeconomic determinants further shape edentulism patterns. Education level exhibits a strong inverse relationship with tooth loss, similarly unstable and low skilled jobs face higher risk of tooth loss compared to those in professional and high-income occupations [3].

Tooth loss is a result of multifactorial process. It consists of biological factors such as caries, periodontal disease and non-biological factors such as accessibility to oral health services, treatment options and underlying systemic diseases [4]. Systemic diseases such as cardiovascular diseases, diabetes, cancer and chronic obstructive pulmonary diseases have strong correlation with several oral diseases which ultimately cause tooth loss or vice versa. Teeth loss causes difficulty in eating leading to lower intake of fruits and vegetables causing increased cholesterol and saturated fats thereby increasing prevalence of obesity. This in turn rises the risk of cardiovascular and gastrointestinal diseases like non-insulin dependent diabetes and its complications leading to severe periodontal disease and tooth loss ultimately [6, 7].

Evidence from literature synthesis shows that edentulous individuals are in a greater risk for different systemic diseases. Therefore, tooth loss must be prevented by proper oral health education and high-level dental care [3]. In a study done in Nepal, prevalence of edentulism was found to be 8.58% in the study sample [8].

Despite of established association, the prevalence of systemic diseases among edentulous individuals remains understudied, particular in Nepal, thus the purpose of this study was to investigate the prevalence of self-reported systemic diseases among edentulous patients visiting Patan Academy of Health Sciences (PAHS), Lalitpur, Nepal. The data obtained from this study will offer actionable insights to optimize coordinated care for edentulous patients with systemic comorbidities.

Methods

A descriptive, cross-sectional study was conducted to determine the prevalence of systemic diseases among edentulous patients visiting department of dentistry, PAHS. The ethical clearance was obtained from institutional review committee, PAHS (Ref: drs1805291179) and written informed consent was taken from each patient. The study duration was two years, from September 2019 to September 2022.

A total of 384 edentulous patient (complete or partial edentulous) of 35 years and above were included in the study considering less than 1% of non-response rate. For categorizing edentulism missing permanent teeth except third molars was considered, both partial and complete edentulism were included. Permanent hopeless teeth i.e. those teeth with severe periodontal disease, teeth having advance infections which did not responded to standard treatment, teeth with extensive decay, which cannot be restored and teeth with abnormal migrations will be included as edentulous space in our study. All individuals below 35 years of age as incidence of tooth loss and edentulism tends to increase significantly with age, no missing permanent tooth and those who are not willing to give written informed consents are excluded from our study.

To improve representativeness and reduce sampling bias, non-probability convenience sampling technique was utilized for sample collection. Sample size was calculated by the formula of descriptive cross-sectional study as,

Where,

= sample size

z = level of confidence (95%) = 1.96

p = estimated or predicted rate for the population proportion (value obtained from previous research conducted by Basnyat KC et al. [4] (i.e., 0.464)

d = absolute margin of error = 5% (0.05)

During the study period, 384 patients consented to participate. Sociodemographic data including age, sex, education level, occupation, medical history, current history of medications for self-reported conditions and dental history were collected through face-to-face interviews. Dental history encompassed local caused of tooth loss (caries, trauma, periodontitis) and self – reported association between tooth loss and systemic diseases.

A comprehensive intraoral examination was then conducted to record and verify missing permanent dentition based on the study selection criteria. For edentulous patients, prosthetic status was categorized as complete dentures, removable partial dentures, fixed partial dentures, dental implants, or no prosthesis.

Statistical analysis

Data was entered in Epidata and exported to SPSS for further analysis. Continuous variables were summarized using mean and standard deviation while categorical variables were summarized using count and percentages. All the data were displayed using frequency distribution tables. The association between continuous variables with systemic disease was tested with the help of independent T test while association of categorical variables was examined with the help of Chi-Square test or Fisher Exact test based on distribution of data. The independent variables which showed p value < 0.20 in the bivariate analysis were tested through a multivariable model of logistic regression analysis to identify predictors of systemic diseases among the study sample. The level of significance was set at 5%.

Results

As shown in Table 1, more than one thirds (35.70%) of the patients reported to be suffering from a systemic condition. The most common systemic condition was Hypertension (21.60%) followed by Diabetes Mellitus (10.70%), respiratory diseases (6.50%) and joint disorders (2.60%). Two of the study patients suffered from multiple systemic conditions i.e., both Diabetes Mellitus and Cardiovascular disease.

Table 1.

Frequency distribution of self-reported systemic conditions (n = 384)

Study Variables	Categories	Count	Percent
Prevalence of self- reported systemic conditions	Yes	137	35.70%
	No	247	64.30%
Types of systemic conditions	Diabetes Mellitus	41	10.70%
	Cardiovascular disease	7	1.80%
	Respiratory disease	16	6.50%
	Gastrointestinal disease	9	2.30%
	Hepatic disease	0	0
	Renal disorders	1	0.30%
	Joint disorders Rheumatoid arthritis	6	1.60%
	Joint disorders Osteoarthritis	6	2.60%
	Hypertension	83	21.60%
	Diabetes Mellitus + cardiovascular disease	2	0.50%
	Cancer	6	1.60%

Among the patients with systemic conditions, more than 10% (12.04%) were not currently under medication and about 8.70% of patients reported that they believe there was a relation between systemic disease and tooth loss (Tables 2 and 3).

Table 2.

Frequency distribution of systemic disease under medication and perception on tooth loss among the study population. (n = 137)

Variables	Categories	Count	Percent
Under medication for systemic conditions	Yes	120	87.60%
	No	17	12.04%
Perception on positive relationship between tooth loss and systemic disease	Yes	12	8.70%
	No	125	91.24%

Table 3.

Association of age and duration of edentulousness with systemic diseases among the study sample (n = 384)

Variables	Systemic disease (+) (mean ± sd) N = 137	Systemic disease (-) (mean ± sd) N = 247	Mean Diff.	95% CI of mean diff.		P value
				Lower	Upper
Age	59.90 ± 12.07	47.23 ± 13.31	12.67	9.97	15.37	< 0.001*
Duration	07.02 ± 6.86	0.061 + 0.72	6.96	6.09	7.83	< 0.001*

*Statistically significant

In the table above, the mean age was significantly higher among the respondents who reported to be living with systemic diseases with mean difference of 12.67 years. Also, mean duration of edentulousness was much higher among the respondents with systemic diseases with p value < 0.001.

Among 384 edentulous participants, 62.50% were females. Educationally, 26.30% had postgraduate or higher qualifications, while only 0.80% were illiterate. Business was the most common occupation (43.50%), with homemakers representing 1.30%.

Occupation showed a significant association with systemic disease presence. Retired respondents had the highest proportion of systemic disease (27.7%), contrasting with a lower proportion (13.14%) among others. The most common cause of tooth loss was caries (64.10%) followed by periodontitis (31.50%) and trauma (4.40%). A total of 80 patients (20.80%) were currently using prosthesis. Among them majority used removable partial denture, followed by complete denture, fixed partial denture, and implant. The cause of tooth loss also differed significantly for those with systemic disease. Within this group, trauma (29.41%) and periodontitis (43.79%) were reported as causes much more frequently compared to participants without systemic diseases. Both the association of occupation with systemic disease and the difference in causes of tooth loss based on systemic disease status were statistically significant (Table 4).

Table 4.

Association of systemic diseases with socio- demographic variables, causes of tooth and type of prosthesis use. (n = 384)

Variables	Categories	Count (total)	Percent (total)	Systemic disease (+) (count, %)	Systemic disease (-) (count, %)	Test value#	P value
Sex	Male	144	37.50%	57 (41.60%)	87 (35.22%)	1.532	0.216
	Female	240	62.50%	80 (58.39%)	160 (64.77%)
Occupation	Business	167	43.50%	63 (45.98%)	104 (42.10%)	26.452	< 0.001*
	Government job	64	16.70%	18 (13.14%)	46 (18.62%)
	Private job	83	21.60%	18 (13.14%)	65 (26.32%)
	Retired	65	16.90%	38 (27.74%)	27 (10.93%)
	Home maker	5	1.30%	0 (0%)	05 (2.02%)
Education	Postgraduate	101	26.30%	45 (32.84%)	56 (22.67%)	11.996	0.062
	Graduate	23	6.00%	12 (8.75%)	11 (4.45%)
	Higher secondary	50	13.00%	20 (14.59%)	30 (60.0%)
	Secondary	107	27.90%	29 (21.16%)	78 (31.57%)
	Primary	72	18.80%	20 (14.59%)	52 (21.05%)
	Literary	28	7.30%	10 (35.71%)	18 (7.28%)
	Illiterate	3	0.80%	01 (0.730)	2 (0.81%)
Cause of tooth loss	Caries	246	64.10%	72 (52.55%)	174 (70.4%)	14.89	< 0.001*
	Periodontitis	121	31.50%	60 (43.79%)	61 (24.69%)
	Trauma	17	4.40%	05 (29.41%)	12 (04.85%)
Types of prosthesis	Complete Denture	20	5.20%	08 (27.58%)	12 (23.53%)	0.162	0.687
	Partial Denture (Removable, Fixed and Implants 0	54, 5,1	14.10%, 1.30%, 0.30%	21 (72.41%)	39 (76.47%)

# Chi-square test or fisher exact test; *statistically significant

Table 5 shows that although age and duration of edentulousness were positively associated with bivariate analysis, their effects were reversed in the multivariable analysis. For one-year increase in age, the odds of having a systemic disease decrease by 5% indicating negative association. Similarly, with one unit increase in the duration of edentulousness, the odds of systemic disease decrease by 82%. This suggests that the relationship observed in bivariate may be confounded by other variables.

Table 5.

Predictors of presence of systemic diseases among the study sample – Logistic regression analysis

Independent variables		Adjusted Odds ratio	95% CI of AOR		P value
			Lower	Upper
Age (in years)		0.180	− 2.231	−1.199	< 0.001*
Duration of edentulousness		0.955	− 0.082	−0.010	0.011*
Occupation	Business (Reference)
	Government job	1.323	−1.005	1.565	0.669
	Private job	0.912	−1.316	1.131	0.882
	Retired	1.031	−1.204	1.265	0.961
	Home maker	810714.01	−2077.21	2104.42	0.990
Education	Postgraduate (reference)
	Graduate	1.018	−2.317	2.353	0.988
	Higher secondary	0.773	−1.463	0.949	0.676
	Secondary	0.980	−1.176	1.136	0.973
	Primary	1.872	−0.929	2.184	0.430
	Literary	0.746	−2.030	1.444	0.741
	Illiterate	9.785	−5.981	10.543	0.588
Cause of tooth loss	Caries (reference)
	Periodontitis	0.956	−0.931	0.840	0.920
	Trauma	0.755	−2.012	1.450	0.750

*Statistically significant

Discussion

Globally, edentulism has been found to be the most prevalent, irreversible condition with higher preponderance for females compared to males as shown by a systematic review and meta analysis from India [9] which is comparable to our study.In terms of complete edentulism, a retrospective study done by Ganapathi et al. (2021)revealed higher prevalence in males [10].

In the current study, prevalence of self- reported systemic diseases among edentulous patients was 35.70%. Among these patients with systemic diseases, 60.58% (83) reported to have hypertension followed by diabetes in 29.90%(41). The current findings were similar to the results of the study done on health related quality of life where they found that their edentulous patient had predominatly hypertension followed by diabetes and osteoporosis [11, 12]. In contrast, Ganapathi et al. (2021)found the prevalance of diabetes was more than that of hypertension followed by other systemic diseases in another study [10].

Evidence report common causes of tooth loss as caries, periodontal disease followed by trauma [13, 14]. Similarly, in our study population, caries (64.10%) was most reported cause of tooth loss followed by periodontitis (31.50.%) and trauma(4.40%). The choice of treatment for replacing missing teeth is typically made after a thorough discussion between the patient and the dentist, as there are several options available, including interim removable prostheses, definitive cast partial dentures, fixed partial dentures, and dental implants [15]. In our population, 79.20% of people had not replaced their missing teeth, 14% of people were wearing removable partial dentures, 5.20% were wearing complete dentures, 1.30% were wearing fixed partial denture and only one person had replaced missing teeth with dental implants. In contrast, Patil et al. (2022)found out that the people prefered fixed partial denture more, followed by removable partial denture and dental implants. Cost effectiveness and need of maintenance influences the choice of substitutes among the patients [16], which were not explored in the current study.

Usually patients visting dental department do not always report their past medical history, may be they consider its unrelated to their dental problems but for the successful result of dental treatment without complications, medical history is essential [5]. In the present study, 87% of the patients took medications for their systemic conditions, which was similar to the findings of the study done by Fernández-Feijoo et al. (2012), where 75% of the patients used medications [5].

The coexistence of systemic diseases and tooth supports the establised bidirectional relationship between oral and systemic heath, particularly periodontitis and chronic inflammation. In this study, individual with systemic disease has significantly higher rates of periodontitis (43.79%) and trauma (29.41%) as more frequent causes of tooth loss compared to their counterparts without systemic diseases. This alings with establised literature highlighting the bidirectional relationship between systemic health and oral diseases. For instance, conditions like diabetes mellitus and cardiovasular diseases are well documented risk factors for periodontits due to impaires immune response, microvacular changes and chronic inflammation, accelerating periodontal tissue destruction and tooth loss [17, 18].

Interestingly, only 8.70% of those with systemic disease acknowledged a relationship between their systemic condition and tooth loss, suggestin low awareness of the oral-systemic-health connection. This gap in perception highlights the urgent need for integrated oral systemic health education, as supported by WHO global oral health strategies [6].

Socio-economic analysis revealed an unexpected pattern. While edentulism has traditionally been associated with lower economic status [19, 20]. this study found that a significant proportion of edentulous participants has postgraduate education (26.30%) and were engaged in business (43.50%) or private sector jobs. These findings suggest a shifiting paradigm, where higher SES groups may also be at risk, potentally due to occupational stress, poor dietary habits, delayed healthcare utilization or neglect of dental care despite financial capacity [21].

The current study shows high proportion of systemic disease, only 20.80% of participants had replaced their missing teeth with prosthesis.The majority of those who did opted for removable partial dentures (14.10%), with very low uptake of implants (0.30%) or fixed prosthesis (1.30%). This may be due to concerns of over cost, maintainace or lack of access to restorative services, as indicated by regional studies [16].

From a statistical perspective, bivariate analysis indicates that both age and edentulous duration were significanfly associated with systemic disease which echoed with the global evidence that aging is a strong predictor of systemic diseases and edentulism [21]. However, logistic regression revealed an inverse relationship between increased age and edentulous duration correlating with a lower likelihood of reporting systemic disease.This can be atrributed to potential confounding or reporting bias, possibly due to survivorship effects or underdiagnosis among older adults [7]. These findings diverge from traditional assumptions that systemic diesease prevalance increases linearly with age and the longer duration of tooth loss.

The NHANES (National health and nutrition examination survey) study by Alyahya et al. (2024) echoes these findings, where they showed that complete edentulism was associated with higher odds of cardiovascular disease, independent of age and comorbidities. Interestingly, stratified model revealed greater risk in middle aged edentulous individuals, suggesting that age modifies the relationship, potentially explaining our model which showed a different pattern with age [22].

To further unravel the biological plausibility of our findings, the longitudinal cohort study by Wu et al. (2025) which provided compelling evidence that tooth loss is independently associated with increased all-cause mortality by 34%. Their mediation analysis links this association to systemic inflammation (via C- reactive protein elevation (CRP), suggesting a pathway where oral disease drives chronic inflammation aligning with inflammatory burden hypothesis, particularly from untreated periodontitis and unsolved infections leading to edentulism [23]. These findings are directly supported by our study’s results, where significantly longer duration of edentulousness among individuals with systemic diseases (mean 7.02 ± 6.86 years) versus those without (0.06 ± years) with a mean difference of 6.96 years (p < 0.001), supports the idea of cumulative inflammatory burden over time contributing to systemic health decline.

Furthermore, trauma and periodontitis were disproportionally reported as cause of tooth loss in individuals with systemic conditions. Periodontitis usually serves as the well-established trigger of chronic inflammation and has been implicated in systemic disease such as diabetes, cardiovascular disease and even cancer [24].

The current study showed a paradoxical inverse association between systemic disease and age/duration of edentulousness, this likely reflects complex biological interactions and reverse causality rather than protective effect. This variation is consistent with the China Health and Retirement Longitudinal Study (CHARLS) which emphasized on multifactorial and bidirectional pathways [23]. This inflammatory theory further explains why conventional regression models might fail to capture these complexities. Linear models assume unidirectional causality and do not account for mediators like inflammation, delayed manifestation of systemic diseases in older edentulous populations [25].

The present study has several limitations that must be considered when interpreting the findings. Firstly, it is a cross-sectional study, thus, we cannot ascertain the cause and effect of systemic diseases on edentulism. Secondly, the study excluded individuals below 35 years of age, which might have omitted early onset edentulism cases, particularly in populations affected by aggressive periodontitis, trauma, or congenital anomalies. Furthermore, the methodology for data collection was self-reported rather than confirmed through clinical and biochemical examinations, which may lead to mislabelling. Similarly, the self-reported causes of tooth loss may not accurately true aetiology. Therefore, the presence of information bias is possible. It is a single centre study using non-probability sampling thus has limited external validity and may not be generalizable to broader populations. Our study was also unable to estimate monthly income of the patients and thus, failed to provide complete picture of socioeconomic status of the study participants.

Although multivariable analysis was used to control for confounding variables, some key variables like dietary habits, physical activity, smoking, alcohol use or psychological stress were not measured and thus may act as unmeasured confounders, which influenced association.

Despite these limitations, the study was strengthened using standardized intraoral examination protocol, clear selection criteria and comprehensive statistical analysis. We believe these findings provide a valuable foundation for future multi centric, longitudinal studies incorporating clinical diagnostic confirmation, socioeconomic stratification, and oral systemic health integration.

Conclusions

Within the limitations of this study, we found that a significant proportion (35.70%) of edentulous patients self-reported to have systemic diseases, predominantly with hypertension and diabetes. A considerable number of individuals remained untreated or unaware of possible link between their tooth loss and systemic conditions, highlighting a critical gap in patient education and interdisciplinary healthcare.

Our analysis revealed a negative association between systemic disease with age and duration of edentulism. This unexpected finding suggest the possiblity of reverse causality, where individuals with systemic diseases may lose teeth earlier in life, rather than edentulism acting as a long term risk factor for systemic conditions.

Additionally, periodontitis was the most prevalant cause of tooth loss among the patients with systemic diseases which align with current scientific evidence. The study also challenges prevailing assumptions that higher education and professional status protect against systemic illness. This suggest that other factors, such as occupational stress, delayed healthcare seeking may elevate risk across socioeconomic strata.

Ultimately, these conclusions are constrained by the study’s methodological limitations, particularly its inability to confirm causal pathways. Thes should be interpreted as generating hypothesis for future research than confirming established relationships.

Abbreviations

PAHS

Patan Academy of Health Sciences

SES

Socio-Economic Status

CHARLS

China health and retirement longitudinal) study

NHANES

National health and nutrition examination survey

Authors’ contributions

AM, SR, SR, MA designed the study. AM and SR collected the data. AM, SR, SR, RAS entered and analyzed the data. AM, SR, RAS, MA wrote main manuscript and prepared tables. RAS, MA, SR supervised the research and interpretation of data. All authors reviewed the Manuscript.

Funding

The study was not funded by any organization or company.

Data availability

The datasets used and analyzed during the study are available from the corresponding author.

Declarations

Ethical approval and consent to participate

This study was conducted after approval of the Institutional Review Committee of Patan Academy of Health Sciences (Ref: drs1805291179). This study was conducted in accordance with the declarations of Helsinki protocol and ethics. Written informed consent was obtained from each patient enrolled in the study and publication was according to the Institutional Review Committee which comes under National regulation of Nepal.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.