Association between Tooth Loss and Hypertension: A Systematic Review ()
1. Introduction
Hypertension is a medical condition in which blood pressure is chronically 140/90 mmHg or higher, a value that is taken as a reference and persists over time [1]. It is estimated to affect 1.56 billion people in 2025 and is defined as a persistent high systemic arterial blood pressure [2]. The evolution of blood pressure is shown in Table 1.
Table 1. Evolution of blood pressure and stage of blood pressure.
Definitions |
Systolic blood pressure (mm/Hg) |
Diastolic blood pressure (mm/Hg) |
Strokes risk |
Optimal blood pressure |
< 120 |
< 80 |
|
Normal blood pressure |
120 - 129 |
80 - 84 |
|
High blood pressure |
130 - 139 |
85 - 89 |
< 15% |
Hypertension stage I (light) |
140 - 159 |
90 - 99 |
15% - 20% |
Hypertension stage II (moderate) |
160 - 179 |
100 - 109 |
20% 30% |
Hypertension stage III (severe) |
≥ 180 |
≥ 110 |
˃30% |
The risk factors for blood pressure are dependent, such as age, sex, obesity, excessive alcohol consumption, smoking, diabetes, high dietary salt intake, physical inactivity and stress [3] [4]. In addition, tooth loss is another risk factor that can lead to the development of high blood pressure.
The concept of viewing the mouth separately from the rest of the body must cease because oral health affects people in general by causing considerable pain and suffering and by changing what people eat, their speech, and their quality of life and well-being [5].
Tooth loss is a separation of the tooth from its supporting structure that can be caused by dental caries, periodontal disease, periapical infection, fractured tooth, failure of endodontic treatment, trauma, infection, oral neoplasia and congenital disorders [6] [7]. Tooth loss and remaining teeth are an important indicator of overall oral health [8] [9].
The missing tooth is one of the leading oral conditions causing disability-adjusted life years in almost all global regions and might have a direct implication on patient psychological health, aesthetics, and dietary/nutrition state [10] [11].
In addition to known risk factors such as obesity, physical inactivity, smoking, and low income, several studies have shown an independent association between tooth loss and elevated blood pressure [12], but about tooth loss and hypertension, there are some controversies.
Al Ahmad et al., 2018 in the Malaysian population, noted an association between tooth loss and hypertension in postmenopausal women [13]. On the other hand, Gordon et al. 2018 reported that postmenopausal women who lost one or more teeth had a 20% higher risk of hypertension [14]. Another study by Da et al. (2019) found an association between tooth loss and hypertension in older Chinese people [15]. A study in the South African population showed that complete edentulousness is a risk indicator for hypertension [16].
However, the literature evokes different conclusions about this association. The association between impaired mastication, including tooth loss and obesity, was suggested in a systematic review [17].
The purpose of this study was to synthesize and analyze the various studies that had been conducted to provide an overview of the scientific advances in the possible association between tooth loss and hypertension.
2. Materials and Methods
This systematic review was reported according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines.
2.1. Search Strategy and Data Sources
Literature search was conducted for English evidence in PubMed and Google Scholar from January 2000 to December 2023. The following keywords were used: Tooth loss, hypertension, and blood pressure. After the electronic search, a manual search was also conducted through the reference lists from original research and review articles.
The inclusion criteria were defined as follows: 1) written in English, 2) published from January 2000 to December 2023, 3) investigating the association between tooth loss and hypertension, 4) conducted on adult human subjects (age ≥ 18 years), and 5) using quantitative methods of data collection. The exclusion criteria were defined as follows: 1) reviews studies or meta-analyses, 2) involving animals, and 3) published in another language than English.
2.2. Data Extraction
Data were extracted from each eligible study by three independent authors (Lubadi E, Mantshumba A, Kumpanya P) using a specifically developed data extraction sheet. Disagreements were resolved by consensus. The following data were extracted from each eligible study: first author, publication year, type of study, number of subjects, mean age, number of tooth loss, mean blood pressure, and key results.
The collected data were recorded on a computer using Microsoft Office Excel 2016 and then stored in a database using SPSS version 20.0 for analysis.
3. Results
Of 14 studies (11 cross-sectional studies [13] [15] [16] [18]-[25], two descriptive studies [12] [26] and one cohort study [27] were included in this systematic review, as shown in the flow chart (Figure 1).
Figure 1. Flow chart of literature search.
The characteristics of the studies are presented in Table 2. Fourteen studies [12] [13] [15] [16] [18] [27] categorized blood pressure into hypertensive and normal according to global criteria. All studies used values of systolic blood pressure (SBP) and diastolic blood pressure (DBP). In terms of the number of teeth, four studies evaluated the number of missing teeth [16] [18] [21] [27]. Regarding the age range of participants in Table 3, six studies included participants aged ≤ 50 years [12] [16] [18] [21] [23] [24] [26].
Two studies used menopausal women [13] [19]. The distribution of countries where the included studies were conducted is as follows in Table 2: Asia 8 [13] [15] [19]-[21] [23] [26] [27]; America 2 [18] [22]; Africa 1 [16]; and Europe 3 [12] [24] [25].
According to the association between the number of remaining/missing teeth and hypertension. The prevalence of hypertension was compared between/among groups with different numbers of remaining teeth in eleven cross-sectional studies [13] [15] [16] [18]-[25] (Table 2). One of the eleven studies showed an inverse association between the number of remaining teeth and hypertension [12]. On the other hand, a different study failed to find an association between the number of remaining teeth and hypertension [22] [25].
Table 2. Characteristics of selected items.
N˚ |
Authors & years |
Country/
sample size |
Type of study |
Gender |
Average age (years) |
Number of teeth lost |
|
Mean BPSBP/DBP(mmHg) |
Key results |
|
|
|
|
|
|
< 10 |
≥ 10 |
|
|
|
Cross sectional |
|
|
|
|
|
|
|
|
1 |
Ayo-yusuf et al. 2008 [16] |
South Africa/9098 |
Cross sectional |
M: 3628
F: 5470 |
45 |
7013 |
2085 |
130/78 |
Total tooth loss is a risk indicator for established hypertension |
2 |
Peres et al. 2012 [18] |
Brazil 1720 |
Cross sectional |
M: 761 F: 959 |
38.1 |
382 |
1338 |
132.9/85 |
Total tooth loss is associated with increased SBP among adults |
3 |
Taguchi et al. 2014 [19] |
Japan/98 |
Cross sectional |
F: 98 |
54.8 |
73 |
25 |
129.1/78.9 |
Tooth loss increased risk of hypertension in postmenopausal |
4 |
Singh et al. 2015 [20] |
India 1480 |
Cross sectional |
M: 718 F: 762 |
58 |
878 |
602 |
153.3/95.2 |
Tooth loss was associated with a higher probability of hypertension among
dental middle age and older adults |
5 |
Hye-Sun Shin 2017 [21] |
South Korea 13561 |
Cross sectional |
M: 5757
F: 7804 |
42.5 |
2114 |
11,447 |
146.7/83 |
Number of teeth may be associated with hypertension after adjusting for age, gender, education, smoking… |
6 |
Maia et al. 2018 [22] |
Brazil 212 |
Cross sectional |
M: 53 F: 159 |
57.5 |
38 |
174 |
130/78.87 |
The annual dental visit and the self-concept of dental treatment need were associated with tooth loss |
7 |
Al Ahmad et al. 2018 [13] |
Malaysia/60 |
Cross sectional |
F: 60 |
59.5 |
26 |
34 |
136.4/79.2 |
Tooth loss is associated with the increase risk of hypertension in postmenopausal |
8 |
Da et al. 2019 [15] |
China 3677 |
Cross sectional |
M: 1644 F: 2033 |
70.23 |
1455 |
2222 |
150/75.9 |
Tooth loss may be associated with severe hypertension among older chinese adults |
9 |
Hosadurga
et al. 2020 [23] |
Malaysia 269 |
Cross sectional |
M: 119 F: 150 |
39.5 |
206 |
63 |
125.3/78.9 |
SBP was higher among the participants with increasing tooth loss |
10 |
Mendes et al. 2021 [24] |
Portugal 10576 |
Cross sectional |
M:4264 F: 6312 |
44.9 |
8111 |
2465 |
135.3/83 |
BP and tooth loss are related, and age is the key indicator in this association |
11 |
Delbruto et al. 2021 [25] |
Portugal 1543 |
Cross sectional |
M: 682 F: 861 |
59.4 |
426 |
1117 |
156.6/77 |
Age captures most of the effect of the association between pulsatile components of BP and severe tooth loss. |
|
Descriptive |
|
|
|
|
|
|
|
|
12 |
Volzke et al. 2006 [12] |
Germany 4185 |
Descriptive |
M: 2035
F: 2150 |
49.5 |
1698 |
2487 |
136.01/83.6 |
There is an inverse association of the number of teeth SBP and hypertension in men |
13 |
Dar Odeh et al. 2019 [26] |
Saudi Arabia 1768 |
Descriptive |
F: 1768 |
31.2 |
1156 |
612 |
142/87.3 |
In a linear regression model, missing teeth was marginally significantly associated with hypertension |
|
Cohort |
|
|
|
|
|
|
|
|
14 |
Woo et al. 2021 [27] |
South Korea 19680 |
Cohort |
M: 11,568 F: 8112 |
51.8 |
19,475 |
205 |
112.1/71 |
Lost of 8 or more teeth was associated with higher risk of developing hypertension |
Legend: SBP: Systolic Blood Pressure; DBP: Diastolic Blood Pressure; BP: Blood Pressure.
Table 3. Articles according to gender and average age.
Authors |
Average age (years) |
Gender |
Male |
Female |
Volzke et al. [12] |
49.5 |
2035 |
2150 |
Ayo-yusuf et al. [16] |
45 |
3628 |
5470 |
Peres et al. [18] |
38.1 |
761 |
959 |
Taguchi et al. [19] |
54.8 |
/ |
98 |
Singh et al. [20] |
58 |
718 |
762 |
Hye-Sun Shin [21] |
42.5 |
5757 |
7804 |
Maia et al. [22] |
57.5 |
53 |
159 |
Al Amad et al. [13] |
59.5 |
/ |
60 |
Da et al. [15] |
70.23 |
1644 |
2033 |
Dar Odeh et al. [26] |
31.2 |
/ |
1768 |
Hosadurga et al. [23] |
39.5 |
119 |
150 |
Woo et al. [27] |
51.8 |
11,568 |
8112 |
Mendes et al. [24] |
44.9 |
4264 |
6312 |
Delbruto et al. [25] |
59.4 |
682 |
861 |
Average/Total |
50.13 |
31,229 |
36,698 |
4. Discussion
This systematic review was conducted to analyze the association between tooth loss and hypertension based on scientific evidence from clinical studies during the last two decades.
The prevalence of hypertension was compared between/among groups with different numbers of remaining teeth in eight cross-sectional studies [16] [18] [19] [21]-[23] [26] [27] (Table 2). On the other hand, two studies failed to find an association between the number of remaining teeth and hypertension [22] [25]. Ten studies analyzed the association between number of missing teeth and hypertension [12] [13] [15] [16] [18]-[21] [26] [27] (Table 2). One of the fourteen studies displayed a positively significant association [27]. Two studies showed that menopausal women with hypertension had a higher number of remaining teeth than those without hypertension [13] [19]. About the association between the number of remaining/missing teeth and SBP/DBP. Fourteen studies analyzed this association [12] [13] [15] [16] [18]-[27] (Table 2). One study demonstrated that the number of remaining teeth was inversely associated with SBP and DBP [12]. In the same study, men with fewer teeth had significantly higher SBP than those with higher teeth, which was significantly higher [12], but this association was not observed in women [13]. The gender showed a female predominance of 54.02% [12] [13] [16] [19]-[25]. This finding could be justified by the greater aesthetic interest that women have in dental restoration. However, men also perceive the loss of teeth as a real castration of their power assets; aesthetic prejudice is less deeply rooted in the psyche of men [9]. What’s more, the cyclical hormonal changes that characterize women’s lives are a favorable factor for the development of periodontal disease, which accounts for 75% of tooth loss [28]. For women, the association between tooth loss and hypertension was marginally or not observed in studies including younger participants (19 - 39 years) [29]. However, in the Völzke’s study including individuals aged 20 - 79 years, the significant association was found among men unlike among women [30].
Two studies reported that populations with a greater number of missing teeth exhibited significantly higher SBP or DBP than those with a smaller number of missing teeth [20] [27].
Regarding the number of tooth loss, the group with less than 10 teeth lost was predominant (63.37%). However, studies that reported a greater number of participants who lost more than 10 teeth revealed a high average BP [15] [20]. In one study, participants with missing teeth > 10 were more times likely to have SBP > 140 mmHg than the participants with missing teeth ≤ 10 among adults [27]. According to the type of studies, we found a predominance of cross-sectional studies with 78.58% [15] [31].
One study demonstrated that the number of remaining teeth was inversely associated with systolic blood pressure and diastolic blood pressure after adjusting for covariates [18]. In another study, men with higher teeth loss had significantly higher systolic blood pressure than those with fewer teeth loss, but this association was not observed in women [30]. Another study showed that the participants with a higher number of remaining teeth exhibited a significantly higher systolic blood pressure than the population with a lower number of remaining teeth, but this association was not observed with diastolic blood pressure [25].
Hosadurga et al., 2020 showed that, the mean systolic blood pressure was higher among the participants who were edentulous than partially edentulous, and it reported also that participants with a greater number of missing teeth exhibited significantly higher systolic blood pressure or diastolic blood pressure than those with a smaller number of missing teeth [23].
One cohort study compared the incidence of hypertension in regard to different numbers of teeth. A significantly higher incidence of hypertension was observed in the population with a lower number of teeth [27]. This study demonstrated that the loss of 10 or more teeth was associated with a higher risk of developing hypertension. Thus, the higher number of lost teeth may be associated with the risk of hypertension.
Therefore, the association between tooth loss and hypertension may be explained by nutritional intake. In addition, tooth loss and inflammation of periodontal pockets due to removed teeth may lead to chronic systemic inflammation and increase the risk of hypertension [32].
Al-Ahmad et al., 2018 showed that group with hypertension had higher mean of number of missing teeth than normal blood pressure group, and it showed that menopausal women with hypertension had a higher number of remaining teeth than those without hypertension [13].
According to Singh et al., 2015, tooth loss was associated with higher systolic blood pressure and peripheral arterial disease among men [20].
Total tooth loss was significantly associated with hypertension. The mechanisms have been proposed to explain the association between tooth loss and hypertension. Due to masticatory insufficiency, tooth loss may alter the eating habits of subjects and so cause less intake of vitamins, fiber and more cholesterol, consequently increasing the risk of hypertension [15].
There are some limitations in this study. Firstly, all studies included in this review were observational studies except one cohort study. Interventional studies are necessary to analyze this relationship. Secondly, some studies could not be included in this study because of a lack of data for real number of participants by tooth loss and hypertension.
The strength of this study is the inclusion of studies with a large number of participants.
5. Conclusions
This study has revealed a significantly higher systolic blood pressure in participants with fewer remaining teeth or more tooth loss and this association is bidirectional.
Future studies are needed to investigate the mechanisms underlying the association between hypertension and tooth loss further.
Acknowledgements
We would like to thank the National Center of Research in Dental Sciences in Kinshasa, Democratic Republic of Congo for his support.