Prevalence and associated factors of denture use among elderly living in rural and urban areas of China: A national cross-sectional study

doi:10.21203/rs.3.rs-3148506/v1

Download PDF

Research Article

Prevalence and associated factors of denture use among elderly living in rural and urban areas of China: A national cross-sectional study

https://doi.org/10.21203/rs.3.rs-3148506/v1

This work is licensed under a CC BY 4.0 License

You are reading this latest preprint version

Backgrounds:

Tooth loss, often considered as an inevitable result of ageing, is one of the most frequently stated problems with older adults worldwide, which entails a negative impact on physical and mental health, as well as quality of life. However, there is urban-rural gap among older adults in both oral health condition and dental service utilization. The study focused on the urban-rural gap in Chinese older population, aiming to describe their tooth loss and denture use status, and explore the associated factors, hoping to provide insights into improving the oral healthcare system in China and other developing countries.

Methods

This cross-sectional study used data collected from May to September in 2020. A stratified, multi-stage cluster sampling design was used to produce nationally representative samples of adults aged 60 years and older. The dependent variable was denture use of the participant. Determinants included demographic characteristics, health status, social support, oral health knowledge and health service utilization. Descriptive analysis was conducted to describe the sample characteristics, and logistic regression analysis was used to identify independent factors associated with denture use among older adults in rural and urban China respectively.

Results

There were significantly urban-rural differences in tooth loss, denture use and health service utilization among Chinese older adults. Urban participants who used dentures tended to have higher oral health knowledge levels (OR = 1.714, 95%CI = 1.280–2.297), have dental check-ups in 6 months (OR = 1.718, 95%CI = 1.267–2.329), and have higher levels of social support (OR = 1.749, 95%CI = 1.323–2.313). Rural participants who were older (70–74: OR = 1.600, 95%CI = 1.010–2.534; 75+: OR = 1.621, 95%CI = 1.016–2.584; 60–64 as the reference group), had higher oral health knowledge levels (OR = 1.933, 95%CI = 1.467–2.545), had dental checkups in 6 months (OR = 1.607, 95%CI = 1.113–2.321), and assessed their health status as higher (OR = 1.431, 95%CI = 1.024–1.998) were more likely to use dentures.

Conclusions

Greater efforts should be made to enhance oral health education and emphasize the importance of regular dental checkups among older population. Targeted focus on different aspects of oral health based on the characteristics of different populations is suggested. Policymakers should be aware of the urban-rural disparity in distribution and utilization of oral health services.

Older people

Oral health

Tooth loss

Denture

Urban-rural gap

Oral health inequality, according to World Health Organization, is an issue based on professional practice, ethical public health policy, and social justice¹. It is a burden of oral disease, which disproportionally affecting people from more disadvantaged backgrounds and vulnerable populations, like the elderly. As the United Nations declared in Decade of Healthy Ageing (2021–2030), oral health is a key indicator of overall health in older age². For the elderly, poor oral health is linked with non-communicable diseases (NCDs), overall frailty and reduced quality of life^3,4. Previous study has shown the urban-rural gap among older adults in both oral health condition and dental service utilization⁵. Therefore, it is crucial to address oral health inequality in the older population.

Tooth loss, often considered as an inevitable result of ageing, is one of the most frequently stated problems with older adults worldwide⁶. For people over 60 years old, almost one in four persons suffers from complete toothlessness or edentulism¹. As the end point of a lifelong history of oral disease, it can limit chewing ability and nutrient intake, affect appearance and articulation, which entails a negative impact on physical and mental health, as well as social function and quality of life^7–10. In the global concerns, the burden of disability-adjusted life years (DALYs) due to tooth loss is estimated to be over 9.5 million¹.

Dentures, as a widely accepted treatment of tooth loss, are prostheses that can replace one or more natural teeth¹¹. A number of works have shown that the harm of tooth loss can be partially counteracted by using dentures, especially in chewing and swallowing function, cognitive health, life expectancy, and quality of life^7,11−13. According to the 7th National Population Census in 2020, people aged 60 and older in China was 264 million, accounting for 18.7% of the total population¹⁴. Among Chinese older population aged 65–74, the average number of remaining teeth was 22.5 in 2015¹⁵. However, only 63.2% of Chinese older adults with missing teeth use dentures¹⁵. Additionally, while much is known about oral health service utilization, less attention has been paid to the factors influencing denture use among the elderly in China.

In 2018, the National Investigation of Resources for Oral Health in China has showed insufficiencies and inequalities in distribution of stomatological staff and institutions nationally. Also, surveys conducted by National Health Commission (2015) have established the significant distinction between rural and urban Chinese seniors, in terms of the proportion of tooth loss and denture use¹⁵. Prior studies have also suggested that oral health service utilization among older adults varies greatly between rural and urban areas, alongside the difference in its relevant factors^16–18. However, there has been little research on tooth loss, denture use and associated factors among rural and urban older adults, both in China or abroad. Addressing on this topic is critical for promoting urban-rural health equality, which can also serve as a reference for other developing countries.

Therefore, in this study, we focused on the urban-rural gap in Chinese older population, aiming to describe their tooth loss and denture use status, and explore the associated factors. By highlighting the disparities between rural and urban China, we hope to provide insights into improving the oral healthcare system in China and other developing countries.

Study design

This cross-sectional study used data collected from May to September in 2020. A stratified, multi-stage cluster sampling design was used to produce nationally representative samples of adults aged 60 years and older. First, we selected six provinces/municipalities (Zhejiang, Jiangxi, Beijing, Gansu, Chongqing, and Liaoning) out of the Six Administrative Regions of mainland China (East, South Central, North, Northwest, Southwest, and Northeast, correspondingly). Second, from each province/municipality, we selected the provincial capital city and randomly selected another city whose Gross Domestic Product (GDP) last year was in the bottom third of the province/municipality. Then, we randomly selected a district (urban) and a county (rural) respectively from each city above. From each district/county, a sub-district/town was also selected randomly. Finally, we conducted the survey in the selected sub-districts and towns, the proportion of the population surveyed was determined according to the urbanization rate of each city.

Population

The participants in this study were recruited from community health centers with collaboration with the family doctors. The inclusion criteria were as follows: (1) 60 years old or above; (2) local residents who had been living in the selected area for more than 6 months prior to the start of the study; (3) signed the informed consent form. Participants who had mental disorders or dementia were excluded from the study.

No less than 250 questionnaires were collected from each city selected; overall, a total of 3056 participants completed the questionnaires. 60 (1.96%) questionnaires were excluded for illegible hand writing. Our analyses used all 2709 participants for whom the variables of interest were available, with no imputation for missing data.

The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Peking University Health Science Center (IRB00001052-19143). All participants provided written or oral informed consent.

Data collection

In principle, the questionnaires should be completed by participants themselves according to their own understanding; if the participant had difficulties in reading or writing, and could not complete the questionnaire independently, an investigator would ask the questions in person. Inductive or suggestive language were forbidden. Informed consents were obtained before participation.

The questionnaire and work procedure were designed by the research team in PKU. All investigators received standard training before the survey. Investigators were required to check every questionnaire item on the spot to avoid any error and ensure data quality; quality control personnel were required to review all the questionnaires on a daily basis.

Variables

Dependent variable:

Denture use of participants was measured by the question "Do you have any missing teeth?" and were required to choose one among four options described below: "No, I don't have any missing teeth", "Yes, and I am currently using dentures", "Yes, and I have intention to use dentures", and "Yes, and I don't have intention to use dentures". We excluded those participants who had no missing teeth in subsequent analysis; then, we defined the second option as “using dentures”, and the last two options were named “without using dentures”. Thus, the participants were divided into two groups by this question.

Independent variables:

Independent variables consisted of demographic characteristics, oral health knowledge, dental checkups, community healthcare and health education service utilization, social support, and health related quality of life.

Demographic characteristics

Demographic characteristics included participants' age, gender, education level, marital status, household income, and urban/rural registered residence.

Dental checkup in 6m

Dental checkups were measured by whether the participant took dental checkups (including preventive and therapeutic checkups) in the 6 months prior to data collection.

Oral health knowledge

In participants’ knowledge of basic oral health for older adults, we simultaneously tested participants' knowledge of dental cavity repairment, missing teeth replacement, and the frequency of dental checkups recommended by experts. The scores were separated into a low and a high level group by median split.

Community healthcare service utilization and community health education service utilization

To assess community healthcare and health education service utilization, we used a set of questions to gauge how often the participants use community healthcare services (free medical consultations, family doctors, physical examinations, exp.) and community health education services (health lectures, health message billboards, health promotion materials, and in-person health education, exp.). Each question used a 4-point Likert scale with 1 = never and 4 = always. Items were scored and summed, then separated into a low and a high level group by median split.

Social support

Social support level was measured by the Social Support Rating Scale (SSRS), which has been applied in a wide range of Chinese populations because of its good reliability and validity. The Scale consisted of 10 items, including objective support (3 items), subjective support (4 items) and the utilization of social support (3 items), with 3 scores in these 3 dimensions, as well as a total social support score ranging from 12 to 66. The scores were also separated into a low and a high level group by median split.

HRQoL and self-assess health status: In order to measure participants' health related quality of life (HRQoL), the EuroQoL-5 Dimensions (EQ-5D) and Visual Analogue Scale (VAS) system were applied. EQ-5D consists of 5 dimensions (mobility, self-care ability, daily activities, pain/discomfort, and anxiety/depression), with each dimension having three possible outcomes (no problems, moderate problems and extreme problems). The answers were grouped by "having no problem in any of the 5 dimensions" and "having some problems in any of the 5 dimensions". The EQ-VAS asked the participant to consider their health state during the past one month, then provides an assessment of current health status on a vertical scale of 0–100, with a higher score indicated better self-assessed health status. The scores were divided into tertiles: lower, medium and higher self-assessed health status.

Data analysis

Data analyses were performed using IBM SPSS Statistical v. 26.0 (IBM, Armonk, NY, USA). The descriptive analysis was used to describe the sample characteristics based on rural and urban registered residence. A chi-square test was applied to explore whether the distribution of variables was significantly different between these two subgroups. We used univariate analysis to identify important variables for logistic regression, with chi-square and Fisher exact tests used. Independent variables with P > 0.20 were removed across the models in the multivariate regression analysis. Multivariate logistic regression analysis was conducted to identify independent factors associated with denture use among older adults in rural and urban China respectively. All P values reported are two-tailed. Statistical significance was set at 0.05.

Sample characteristics

A total of 2709 participants were included in the analysis Table 1 and Table 2: 52.01% (1,409/2,709) were urban residents, and 47.99% (1,300/2,709) were rural residents. The overall incidence of tooth loss was 77.2% (2092), 32.85% (890) older people had missing teeth but never replaced them.

There were some significantly urban-rural differences in most of the assessed variables: For rural participants, 80.54% (1047) had missing teeth, 38.62% (502) didn’t use dentures, with proportions of 74.17% (1045) and 27.54% (388), correspondingly, in urban participants. Compared with urban participants, rural participants were significantly older, more likely to be male, less educated, widowed, from less affluent families, and self-reported less healthy; Besides, rural participants had relatively lower levels of oral health knowledge, Community healthcare service utilization, social support (and its dimension utilization of social support), and dental checkups than urban participants (all P < 0.05). For health-related quality of life, there was no significant difference between rural versus urban participants. After stratified by age groups, in 2 out of 4 age groups, the rate of missing teeth is significantly higher in rural participants than urban ones (65-69: 68.29% vs 76.43%, P=0.008; 70-74: 76.72% vs 83.16%, P=0.031).

Table 1 Sociodemographic characteristics of the study population, urban versus rural registered residence

Variables	Overall(N=2709) n(%)		Urban(N=1409) n(%)		Rural(N=1300) n(%)		chi-square	p value^b
Province/municipality
Zhejiang	475	(17.53)	329	(23.35)	146	(11.23)	108.190	＜0.001^***
Jiangxi	458	(16.91)	200	(14.19)	258	(19.85)
Beijing	473	(17.46)	248	(17.60)	225	(17.31)
Gansu	469	(17.31)	276	(19.59)	193	(14.85)
Chongqing	408	(15.06)	181	(12.85)	227	(17.46)
Liaoning	426	(15.73)	175	(12.42)	251	(19.31)
Age group							9.692	0.021^*
60-64	391	(14.43)	226	(16.04)	165	(12.69)
65-69	854	(31.52)	451	(32.01)	403	(31.00)
70-74	722	(26.65)	348	(24.70)	374	(28.77)
75+	742	(27.39)	384	(27.25)	358	(27.54)
Gender							10.941	＜0.001^***
Male	1205	(44.48)	584	(41.45)	621	(47.77)
Female	1504	(55.52)	825	(58.55)	679	(52.23)
Education level							628.683	＜0.001^***
Primary school or less	1332	(49.17)	383	(27.18)	949	(73.00)
Middle school	792	(29.24)	529	(37.54)	263	(20.23)
High school	410	(15.13)	326	(23.14)	84	(6.46)
College or higher	175	(6.46)	171	(12.14)	4	(0.31)
Marital status							21.385	＜0.001^***
Never married	12	(0.44)	6	(0.43)	6	(0.46)
Married	2215	(81.76)	1162	(82.47)	1053	(81.00)
Divorced	53	(1.96)	42	(2.98)	11	(0.85)
Widowed	429	(15.84)	199	(14.12)	230	(17.69)
Household income^a							951.926	＜0.001^***
Low	700	(25.84)	40	(2.84)	660	(50.77)
Low and middle	1296	(47.84)	756	(53.66)	540	(41.54)
Upper middle	596	(22.00)	516	(36.62)	80	(6.15)
High	117	(4.32)	97	(6.88)	20	(1.54)
Basic medical insurance							1612.757	＜0.001^***
Urban Employee Basic Medical Insurance	909	(33.55)	887	(62.95)	22	(1.69)
Urban Resident Basic Medical Insurance	741	(27.35)	380	(26.97)	361	(27.77)
Government medical insurance	80	(2.95)	73	(5.18)	7	(0.54)
New Cooperative Medical Scheme	954	(35.22)	58	(4.12)	896	(68.92)
None of the above	25	(0.92)	11	(0.78)	14	(1.08)

a. Income level was classified as low, low and middle, upper middle, and high. For urban residents (personal monthly income): low, RMB < 600 (USD < 91); low and middle, RMB 600~3500 (USD 91~533); upper middle, RMB 3500~6500 (USD 533~990), and high, RMB ≥ 6500 (USD ≥ 990). For rural residents (household annually income): low, RMB < 17,000 (USD 2589); low and middle, RMB 17,000~65,000 (USD 2589~9900); upper middle, RMB 65,000~100,000 (USD 9900~15,231), and high, RMB ≥ 100,000 (USD ≥ 15,231). The same hereinafter.

b. *P < .05; **P < .01; ***P < .001. The same hereinafter.

Table 2 Health-related characteristics of the study population, urban versus rural registered residence

Variables	Overall(N=2709) n(%)		Urban(N=1409) n(%)		Rural(N=1300) n(%)		p value
Dental checkup in 6m							＜0.001^***
Yes	584	(21.56)	411	(29.17)	173	(13.31)
No	2125	(78.44)	998	(70.83)	1127	(86.69)
Oral health knowledge							＜0.001^***
Correct	1490	(55.00)	952	(67.57)	538	(41.38)
Wrong	1219	(45.00)	457	(32.43)	762	(58.62)
Community health education service utilization							＜0.001^***
Low level	960	(35.44)	443	(31.44)	517	(39.77)
High level	1749	(64.56)	966	(68.56)	783	(60.23)
Community healthcare service utilization							0.005^**
Low level	818	(30.20)	392	(27.82)	426	(32.77)
High level	1891	(69.80)	1017	(72.18)	874	(67.23)
Social support
Objective support							0.920
Low level	1506	(55.59)	782	(55.50)	724	(55.69)
High level	1203	(44.41)	627	(44.50)	576	(44.31)
Subjective support							0.169
Low level	1528	(56.40)	777	(55.15)	751	(57.77)
High level	1181	(43.60)	632	(44.85)	549	(42.23)
Utilization of social support							＜0.001^***
Low level	1530	(56.48)	746	(52.95)	784	(60.31)
High level	1179	(43.52)	663	(47.05)	516	(39.69)
Total score							0.045^*
Low level	1244	(45.92)	621	(44.07)	623	(47.92)
High level	1465	(54.08)	788	(55.93)	677	(52.08)
Self-assess health status							＜0.001^***
Lower	858	(31.67)	394	(27.96)	464	(35.69)
Medium	908	(33.52)	472	(33.50)	436	(33.54)
Higher	943	(34.81)	543	(38.54)	400	(30.77)
HRQoL							0.247
Have no problem	1805	(66.63)	953	(67.64)	852	(65.54)
Have some problems	904	(33.37)	456	(32.36)	448	(34.46)
Missing teeth and denture use							＜0.001^***
Have no missing teeth	617	(22.78)	364	(25.83)	253	(19.46)
Have used dentures	1202	(44.37)	657	(46.63)	545	(41.92)
Intent to use dentures	333	(12.29)	172	(12.21)	161	(12.38)
Have no intention to use dentures	557	(20.56)	216	(15.33)	341	(26.23)

Characteristics of denture use

Urban participants who used dentures tended to have higher oral health knowledge levels (OR=1.714, 95%CI=1.280-2.297), have dental check-ups in 6 months (OR=1.718, 95%CI=1.267-2.329), and have higher levels of social support (OR=1.749, 95%CI=1.323-2.313).

Rural participants who were older (70-74: OR=1.600, 95%CI=1.010-2.534; 75+: OR=1.621, 95%CI=1.016-2.584; 60-64 as the reference group), had higher oral health knowledge levels (OR=1.933, 95%CI=1.467-2.545), had dental checkups in 6 months (OR=1.607, 95%CI=1.113-2.321), and assessed their health status as higher (OR=1.431, 95%CI=1.024-1.998; lower self-assessed health status as the reference group) were more likely to use dentures. The results of univariate analysis and multivariate logistic regression analysis are presented in Table 3-6.

Table 3 Univariate analysis of denture use in sociodemographic characteristics, by registered residence(N=1045:1047)

Variables		Urban (N, %)	p value	Rural (N, %)	p value
Age group			0.679		0.266
	60-64	94(60.65)		57(49.14)
	65-69	198(64.29)		148(48.05)
	70-74	173(64.79)		170(54.66)
	75+	192(60.95)		170(54.49)
Gender			0.567		0.635
	Male	281(61.89)		258(51.29)
	Female	376(63.62)		287(52.76)
Education level			0.021^*		0.373
	Primary school or less	163(56.01)		394(50.71)
	Middle school	244(63.38)		110(54.46)
	High school	165(68.18)		39(60.94)
	College or higher	85(66.93)		2(50)
Marital status			0.996		0.669
	Married	535(62.89)		440(52.38)
	Others	122(62.89)		105(50.72)
Household income			0.160		0.045
	Low	16(47.06)		249(48.35)
	Low and middle	347(62.19)		253(56.22)
	Upper middle	245(64.14)		39(55.71)
	High	49(69.01)		4(33.33)
Basic medical insurance			0.001^**		<0.001
	Urban Employee Basic Medical Insurance	445(67.22)		11(55)
	Urban Resident Basic Medical Insurance	151(55.51)		192(63.16)
	Government medical insurance	36(62.07)		3(50)
	New Cooperative Medical Scheme	19(43.18)		334(47.31)
	None of the above	6(66.67)		5(45.45)

a. Fisher's exact test was used because of the small expected values

Table 4 Univariate analysis of denture use in health-related characteristics, by registered residence(N=1045:1047)

Variables		Urban (N, %)	p value	Rural (N, %)	p value
Oral health knowledge			<0.001^***		<0.001
	High level	472(68.6)		268(63.81)
	Low level	185(51.82)		277(44.18)
Dental checkup in 6m			<0.001^***		0.001
	Yes	236(72.84)		103(64.38)
	No	421(58.39)		442(49.83)
Community health education service utilization			0.003^**		0.095
	Low level	181(56.21)		192(48.73)
	High level	476(65.84)		353(54.06)
Community healthcare service utilization			0.172		0.358
	Low level	174(59.59)		169(50)
	High level	483(64.14)		376(53.03)
Social support			<0.001^***		0.019
	Low level	271(54.86)		230(48.12)
	High level	386(70.05)		315(55.36)
Self-assessed health status			0.021^*		0.053
	Lower	185(56.75)		206(51.76)
	Medium	225(66.37)		168(47.86)
	Higher	247(65)		171(57.38)
HRQoL					0.118
	Have no problem	442(65.29)		334(50.23)
	Have some problems	215(58.42)		211(55.24)

Table 5 Multivariate logistic regression analysis of factors associated with denture use among older adults in urban China

Variables		OR	OR 95%CI		P
			lower	upper
Age group
	60-64	ref
	65-69	1.343	0.877	2.057	0.176
	70-74	1.522	0.979	2.367	0.062
	75+	1.330	0.861	2.057	0.199
Gender
	Male	ref
	Female	1.115	0.843	1.475	0.446
Education level
	Primary school or less	ref
	Middle school	0.997	0.701	1.418	0.985
	High school	1.328	0.880	2.005	0.177
	College or higher	0.953	0.571	1.592	0.854
Marital status
	Married	ref
	Others	1.258	0.870	1.819	0.223
Household income
	Low	ref
	Low and middle	1.260	0.592	2.684	0.549
	Upper middle	1.118	0.507	2.468	0.782
	High	1.429	0.562	3.632	0.453
Basic medical insurance
	None of the following	ref
	Urban Employee Basic Medical Insurance	1.024	0.233	4.499	0.975
	Urban Resident Basic Medical Insurance	0.689	0.156	3.037	0.623
	Government medical insurance	0.639	0.133	3.072	0.576
	New Cooperative Medical Scheme	0.545	0.111	2.673	0.455
Oral health knowledge
	Low level	ref
	High level	1.714	1.280	2.297	<0.001
Dental checkup in 6m
	No	ref
	Yes	1.718	1.267	2.329	<0.001
Community health education service utilization
	Low level	ref
	High level	1.189	0.874	1.617	0.271
Community healthcare service utilization
	Low level	ref
	High level	1.041	0.758	1.430	0.805
Social support
	Low level	ref
	High level	1.749	1.323	2.313	<0.001
Self-assessed health status
	Lower	ref
	Medium	1.228	0.875	1.724	0.235
	Higher	1.024	0.726	1.446	0.891
HRQoL
	Have no problem	ref
	Have some problems	0.786	0.586	1.054	0.108

Table 6 Multivariate logistic regression analysis of factors associated with denture use among older adults in rural China

Variables		OR	OR 95%CI		P
			lower	upper
Age group
	60-64	ref
	65-69	1.075	0.684	1.689	0.753
	70-74	1.600	1.010	2.534	0.045
	75+	1.621	1.016	2.584	0.042
Gender
	Male	ref
	Female	1.181	0.908	1.538	0.215
Education level
	Primary school or less	ref
	Middle school	1.015	0.727	1.418	0.929
	High school	0.973	0.547	1.730	0.925
	College or higher	0.918	0.105	8.012	0.939
Marital status
	Married	ref
	Others	0.908	0.643	1.281	0.581
Household income
	Low	ref
	Low and middle	1.151	0.874	1.516	0.316
	Upper middle	1.132	0.659	1.944	0.653
	High	0.603	0.169	2.150	0.436
Basic medical insurance
	None of the following	ref
	Urban Employee Basic Medical Insurance	0.803	0.170	3.783	0.781
	Urban Resident Basic Medical Insurance	1.675	0.471	5.952	0.425
	Government medical insurance	0.790	0.096	6.521	0.827
	New Cooperative Medical Scheme	0.940	0.270	3.276	0.923
Oral health knowledge
	Low level	ref
	High level	1.933	1.467	2.545	<0.001
Dental checkup in 6m
	No	ref
	Yes	1.607	1.113	2.321	0.011
Community health education service utilization
	Low level	ref
	High level	0.974	0.737	1.288	0.856
Community healthcare service utilization
	Low level	ref
	High level	1.041	0.789	1.374	0.774
Social support
	Low level	ref
	High level	1.168	0.891	1.532	0.260
Self-assessed health status
	Lower	ref
	Medium	0.955	0.702	1.301	0.772
	Higher	1.431	1.024	1.998	0.036
HRQoL
	Have no problem	ref
	Have some problems	1.099	0.825	1.464	0.518

Our study is the first to focus on the urban-rural gap of tooth loss and denture use among Chinese older adults, describe the current status of missing teeth and denture use, and explore the associated factors. According to our results, there are significant differences in the status of missing teeth and denture use between rural and urban older Chinese population; Oral health knowledge and dental checkups were found to be associated with denture use in both rural and urban older adults. Additionally, our findings indicate the difference between factors associated with the denture use of urban versus rural older adults: for urban older adults, denture use is also related to social support levels; meanwhile, for rural ones, denture use is related to their age and self-assessed health status.

The findings of this study showed significantly lower levels in oral health knowledge, dental checkups, denture use, community healthcare and health education service utilization among the rural elderly population; Plus, there was a significant gap between rural and urban older adults in tooth loss status, even if the influence of age was controlled. These results corroborate the findings of a great deal of the previous work in oral health status and oral health care, thus confirm the idea that urban-rural disparities are common in the field of oral health^16–19. Oral health promotion in rural areas is more challenging than in urban areas.

Consistent with previous studies of oral health care utilization, the current study found that oral health knowledge level and dental checkups were associated with denture use among both urban and rural older adults^20–22. This reflects the importance of health education and regular dental checkups. In fact, the "Oral Health Guide for Chinese Residents: Elderly" released by National Health Commission in 2009 emphasizes that the elderly should "have oral health checkups at least once every six months" and "have a relatively complete dentition"²³. In spite of that, this survey still revealed a lack of oral health knowledge and behaviors among older adults. A part of this could be due to the insufficiency and uneven distribution of dental clinics nationally²⁴.

In addition to the difference in the current status of denture use, it’s interesting to note that the factors associated with denture use differed between urban and rural elderly. For rural older adults, age is a major factor, probably due to their increased rate of tooth loss and denture needs²⁵. Meanwhile, with a higher level of oral health knowledge, urban older adults may be more concerned about oral health, and replace their missing teeth at a younger age, thus their rate of denture use in different age groups is comparable, and higher than that of the rural older adults in the same age group. In addition, rural older adults who assessed themselves as being in better health status were more likely to use dentures. This result may be explained by the fact that denture use facilitates swallowing function, nutritional intake and other physiological functions for older adults, which improves their physical health^26,27; Another possible explanation for this is that older adults who had better health literacy, might value both somatic and oral health highly, which leads to better health condition and behaviors, such as denture use²⁸.

As for urban elderly, higher level of social support was associated with more denture use. In accordance with the present result, previous studies have demonstrated that social interaction and participation may provide older adults with motivation and resources to promote oral health care utilization^29–32. People with poor oral health are more likely to be socially isolated, which is another possible explanation. This urban-rural difference may suggest that urban older adults are motivated to use dentures more by their social life, while rural older adults are more concerned with their own needs. As a consequence, it might be efficient for health educators to provide different types of health-promoting services, respectively, for urban and rural residents: For example, engaging urban elderly in oral health activities with much interaction, and organizing free dental checkups in rural areas.

In contrast to earlier findings, however, the results of this study did not show any statistically significant association in other personal characteristics such as the household income. This discrepancy could be attributed to the difference between denture use and other oral health care utilization, for example, the price of different types of dentures varies widely, and there are products available regardless of income. Additionally, the findings of the current study are contrary to previous studies which have suggested that better dental insurance plans promote the elderly’s oral health care utilization^18,33−35. This inconsistency may be due to the fact that denture fitting is still considered as a medical cosmetic service in the current medical system, and none of the basic medical insurance includes dentures in their coverage.

There were some limitations in the current study that have to be considered, however. First, given its cross-sectional study design, no causal relationships can be established between denture use and underlying determinants. Second, need factors such as number of missing teeth and effect of tooth loss on oral function were not available from the survey, consequently these factors were not included in the analyses. Research shows that chewing ability of the elderly is affected not only by the number of remaining teeth, but also their location and distribution³⁶; The retention of not less than 20 fully-functional natural teeth is sufficient to meet most oral functional demands, such as oral chewing function, aesthetics, articulation and social interaction^36,37. Thus, the need for dentures should be individualized. Third, older adults with mental disorders or dementia, whose health status strongly affected by denture use, were excluded from the study. Older adults with cognitive impairment are more likely to be edentulous, however, when they lose their teeth, they are also more unlikely to use dentures, even if research has confirmed that denture use is able to counteract the negative impact of tooth loss on cognitive function^12,38. Finally, since the data collected was self-reported, recall bias might have been introduced.

Notwithstanding these limitations, this study offers valuable insights into factors relevant to denture use and urban-rural disparities. Further studies could pay attention to the differences in various types of non-natural teeth, as partial or complete, removable or implant-retained fixed dentures. Moreover, the issue of denture use among elderly with poor self-care ability is also an intriguing one which could be usefully explored in further research.

Therefore, greater efforts should be made to enhance oral health education and emphasize the importance of regular dental checkups among older population. Targeted focus on different aspects of oral health based on the characteristics of different populations is suggested. Another important practical suggestion is that the policymakers should be aware of the urban-rural disparity in distribution and utilization of oral health services. A reasonable approach to tackle this issue could be to accelerate the construction of dental healthcare institution in rural areas, and expand basic medical insurance coverage for necessary denture fitting services.

NCDs: Non-Communicable Diseases

DALYs: Disability-Adjusted Life Years

GDP: Gross Domestic Product

HRQoL: Health Related Quality of Life

EQ-5D: the EuroQoL-5 Dimensions

VAS: Visual Analogue Scale

Ethics approval and consent to participate: The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Peking University Health Science Center (IRB00001052-19143). Our study included participants whose education level were ‘primary or less’, but it only means they had no formal diploma or the ability to read written language, not that they had no verbal comprehension. For these participants, the investigator will detailly explain the meaning of the informed consent face to face, to ensure that they fully understand the informed consent, and voluntarily participate in the study. After that, we collected their written signature on the print-out informed consent. All participants provided written or oral informed consent. In China's ethical requirements, there is no provision that "the illiterate elderly need legal representatives to sign informed consent forms".

Consent for publication: Not applicable.

Availability of data and materials: The datasets generated and analyzed during the current study are not publicly available due to participants’ privacy reasons but are available from the corresponding author on reasonable request.

Competing interests: The authors declare that they have no competing interests.

Funding: This research received no external funding.

Authors' contributions:

Conceptualization, Y.L. (Yuxin Eva Lin), Y.J., W.C. and C.C.;

Data curation, Y.L. (Yuxin Eva Lin), M.C., Y.S., Y.L. (Yuting Lin), X.Z., Y.J., W.C. and C.C.;

Formal analysis, Y.L. (Yuxin Eva Lin);

Investigation,; M.C., Y.L. (Yuting Lin);

Methodology, Y.L. (Yuxin Eva Lin), X.Z., Y.J., W.C. and C.C.;

Project administration, C.C.;

Resources, W.C. and C.C.;

Software, Y.L. (Yuxin Eva Lin);

Supervision, X.Z., M.C., Y.J., Y.S., Y.L. (Yuting Lin), W.C. and C.C.;

Validation, X.Z., Y.J., W.C. and C.C.;

Writing—original draft, Y.L. (Yuxin Eva Lin);

Writing—review and editing, Y.L. (Yuxin Eva Lin), X.Z., M.C., Y.J., Y.S., Y.L. (Yuting Lin), W.C. and C.C.

All authors have read and agreed to the published version of the manuscript.

Acknowledgements:

We appreciate the community health service centers in Xicheng and Daxing Districts, Beijing, for their kind support and assistance. We also appreciate the generous help and support from Provincial Center for Disease Control and Prevention in Zhejiang; Provincial Patriotic Health and Health Promotion Center in Jiangxi; Provincial Health Education Center in Chongqing, Liaoning and Gansu. Finally, we want to thank all the investigators, coordinators, colleagues and participants who have been engaged in this study.

World Health O. Global oral health status report: towards universal health coverage for oral health by 2030. World Health Organization; 2022.
Organization WH. UN Decade of Healthy Ageing. Accessed January 6th, 2023. https://www.who.int/initiatives/decade-of-healthy-ageing
Patel J, Wallace J, Doshi M, et al. Oral health for healthy ageing. Lancet Healthy Longev. Aug 2021;2(8):e521-e527. doi:10.1016/s2666-7568(21)00142-2
Seitz MW, Listl S, Bartols A, et al. Current Knowledge on Correlations Between Highly Prevalent Dental Conditions and Chronic Diseases: An Umbrella Review. Prev Chronic Dis. Sep 26 2019;16:E132. doi:10.5888/pcd16.180641
Vargas CM, Yellowitz JA, Hayes KL. Oral health status of older rural adults in the United States. J Am Dent Assoc. Apr 2003;134(4):479-86. doi:10.14219/jada.archive.2003.0199
Organization WH. Oral Health. Updated 2022.11.18. Accessed 12.08, 2022. https://www.who.int/news-room/fact-sheets/detail/oral-health
Watanabe Y, Okada K, Kondo M, Matsushita T, Nakazawa S, Yamazaki Y. Oral health for achieving longevity. Geriatr Gerontol Int. Jun 2020;20(6):526-538. doi:10.1111/ggi.13921
Brennan DS, Spencer AJ, Roberts-Thomson KF. Tooth loss, chewing ability and quality of life. Qual Life Res. Mar 2008;17(2):227-35. doi:10.1007/s11136-007-9293-2
Bortoluzzi MC, Traebert J, Lasta R, Da Rosa TN, Capella DL, Presta AA. Tooth loss, chewing ability and quality of life. Contemp Clin Dent. Oct 2012;3(4):393-7. doi:10.4103/0976-237x.107424
Gerritsen AE, Allen PF, Witter DJ, Bronkhorst EM, Creugers NH. Tooth loss and oral health-related quality of life: a systematic review and meta-analysis. Health and Quality of Life Outcomes. 2010;8(1):126. doi:10.1186/1477-7525-8-126
Furuta M, Yamashita Y. Oral Health and Swallowing Problems. Current Physical Medicine and Rehabilitation Reports. 2013;1(4):216-222. doi:10.1007/s40141-013-0026-x
Yang HL, Li FR, Chen PL, Cheng X, Mao C, Wu XB. Tooth Loss, Denture Use, and Cognitive Impairment in Chinese Older Adults: A Community Cohort Study. J Gerontol A Biol Sci Med Sci. Jan 7 2022;77(1):180-187. doi:10.1093/gerona/glab056
John MT, Slade GD, Szentpétery A, Setz JM. Oral health-related quality of life in patients treated with fixed, removable, and complete dentures 1 month and 6 to 12 months after treatment. Int J Prosthodont. Sep-Oct 2004;17(5):503-11.
China NBoSotPsRo. Main data of the seventh national census Updated 2021-05-11. Accessed 12.08, 2022. http://www.stats.gov.cn/tjsj/zxfb/202105/t20210510_1817176.html
Commission NHaFP. Press Conference on the results Obtained from the 4th national oral health epidemiology survey. Updated 2017-09-19. Accessed 12.08, 2022. http://www.gov.cn/xinwen/2017-09/19/content_5226124.htm#1
Ogunbodede EO, Kida IA, Madjapa HS, et al. Oral Health Inequalities between Rural and Urban Populations of the African and Middle East Region. Adv Dent Res. Jul 2015;27(1):18-25. doi:10.1177/0022034515575538
Wen PC, Lee CB, Chang YH, Ku LE, Li CY. Demographic and rural-urban variations in dental service utilization in Taiwan. Rural Remote Health. Jul-Sep 2017;17(3):4161. doi:10.22605/rrh4161
Khan A, Thapa JR, Zhang D. Preventive Dental Checkups and Their Association With Access to Usual Source of Care Among Rural and Urban Adult Residents. J Rural Health. Sep 2017;33(4):419-426. doi:10.1111/jrh.12271
Qi X, Qu X, Wu B. Urban-Rural Disparities in Dental Services Utilization Among Adults in China's Megacities. Front Oral Health. 2021;2:673296. doi:10.3389/froh.2021.673296
Bottenberg P, Vanobbergen J, Declerck D, Carvalho JC. Oral health and healthcare utilization in Belgian dentate adults. Community Dent Oral Epidemiol. Oct 2019;47(5):381-388. doi:10.1111/cdoe.12484
Xu M, Cheng M, Gao X, et al. Factors associated with oral health service utilization among adults and older adults in China, 2015-2016. Community Dent Oral Epidemiol. Feb 2020;48(1):32-41. doi:10.1111/cdoe.12497
Shahrabani S. Factors affecting oral examinations and dental treatments among older adults in Israel. Israel Journal of Health Policy Research. 2019;8(1)doi:10.1186/s13584-019-0312-x
China NHCo. Oral Health Guide for Chinese Residents. Accessed 12.02, 2022. http://www.nhc.gov.cn/wjw/jkshfs/201304/be0eb756d0b44fadbee65ad64ad8ba06.shtml
Sun XY, Yuan C, Wang XZ, et al. Report of the National Investigation of Resources for Oral Health in China. Chin J Dent Res. 2018;21(4):285-297. doi:10.3290/j.cjdr.a41087
Limpuangthip N, Purnaveja S, Somkotra T. Predisposing and enabling factors associated with public denture service utilization among older Thai people: a cross-sectional population-based study. BMC Oral Health. 2019;19(1)doi:10.1186/s12903-019-0923-1
Furuta M, Komiya-Nonaka M, Akifusa S, et al. Interrelationship of oral health status, swallowing function, nutritional status, and cognitive ability with activities of daily living in Japanese elderly people receiving home care services due to physical disabilities. Community Dent Oral Epidemiol. Apr 2013;41(2):173-81. doi:10.1111/cdoe.12000
Lee S, Sabbah W. Association between number of teeth, use of dentures and musculoskeletal frailty among older adults. Geriatr Gerontol Int. Apr 2018;18(4):592-598. doi:10.1111/ggi.13220
Reda SM, Krois J, Reda SF, Thomson WM, Schwendicke F. The impact of demographic, health-related and social factors on dental services utilization: Systematic review and meta-analysis. J Dent. Aug 2018;75:1-6. doi:10.1016/j.jdent.2018.04.010
Metcalf SS, Northridge ME, Widener MJ, Chakraborty B, Marshall SE, Lamster IB. Modeling Social Dimensions of Oral Health Among Older Adults in Urban Environments. Health Education & Behavior. 2013;40(1_suppl):63S-73S. doi:10.1177/1090198113493781
Gironda MW, Maida C, Marcus M, Wang Y, Liu H. Social support and dental visits. J Am Dent Assoc. Feb 2013;144(2):188-94. doi:10.14219/jada.archive.2013.0098
Burr JA, Lee HJ. Social relationships and dental care service utilization among older adults. J Aging Health. Mar 2013;25(2):191-220. doi:10.1177/0898264312464497
Herkrath FJ, Vettore MV, Werneck GL. Contextual and individual factors associated with dental services utilisation by Brazilian adults: A multilevel analysis. PLOS ONE. 2018;13(2):e0192771. doi:10.1371/journal.pone.0192771
Kohli R, Sehgal HS, Nelson S, Schwarz E. Oral health needs, dental care utilization, and quality of life perceptions among Oregonian seniors. Spec Care Dentist. Mar 2017;37(2):85-92. doi:10.1111/scd.12221
Jang Y, Yoon H, Park NS, Chiriboga DA. Oral Health and Dental Care in Older Asian Americans in Central Texas. Journal of the American Geriatrics Society. 2017;65(7):1554-1558. doi:10.1111/jgs.14832
Kim H-N, Han S-J, Jun E-J, Kim J-B. Factors Related to Oral Healthcare Service Utilization among Korean Adults Aged 25–79 Years. International Journal of Environmental Research and Public Health. 2020;17(17):6032. doi:10.3390/ijerph17176032
Naka O, Anastassiadou V, Pissiotis A. Association between functional tooth units and chewing ability in older adults: a systematic review. Gerodontology. Sep 2014;31(3):166-77. doi:10.1111/ger.12016
Witter DJ, van Palenstein Helderman WH, Creugers NH, Käyser AF. The shortened dental arch concept and its implications for oral health care. Community Dent Oral Epidemiol. Aug 1999;27(4):249-58. doi:10.1111/j.1600-0528.1998.tb02018.x
Mac Giolla Phadraig C, McCallion P, Cleary E, et al. Total tooth loss and complete denture use in older adults with intellectual disabilities in Ireland. J Public Health Dent. Spring 2015;75(2):101-8. doi:10.1111/jphd.12077

No competing interests reported.

Download PDF

Editorial decision: Revision requested
18 Mar, 2024
Reviews received at journal
17 Mar, 2024
Reviewers agreed at journal
05 Mar, 2024
Reviews received at journal
23 Feb, 2024
Reviewers agreed at journal
20 Feb, 2024
Reviews received at journal
19 Dec, 2023
Reviewers agreed at journal
17 Dec, 2023
Reviewers invited by journal
07 Aug, 2023
Editor assigned by journal
02 Aug, 2023
Editor invited by journal
01 Aug, 2023
Submission checks completed at journal
01 Aug, 2023
First submitted to journal
07 Jul, 2023

You are reading this latest preprint version

Prevalence and associated factors of denture use among elderly living in rural and urban areas of China: A national cross-sectional study

Status:

Version 1

Abstract

Backgrounds:

Methods

Results

Conclusions

BACKGROUND

METHODS

Study design

Population

Data collection

Variables

Dependent variable:

Independent variables:

Data analysis

RESULTS

DISCUSSION

Abbreviations

Declarations

References

Additional Declarations

Status:

Version 1