Obesity and dental caries in Saudi Arabia: a correlated study

Abstract

Background

Obesity and dental caries are two major global public health concerns. There have been conflicting reports about the relationship between obesity and dental caries. This study intends to examine the link between obesity and dental caries across the five regions of Saudi Arabia.

Methods

The study involved 380 participants, which was a cross-sectional survey, with an age range of 6 to 14. We distributed a self-reported questionnaire to assess the participants body mass index (BMI) and caries (dmft/DMFT). In this study, descriptive analysis, student t-test, one-way analysis of variance (ANOVA), and multiple linear regression analysis were used.

Results

The study comprised 380 respondents, consisting of females (60.8%) and males (39.2%), with a mean age of 9.1 years and mean BMI of 26.3. The prevalence of caries among the study respondents was 66.6% (Table 2), and this prevalence was higher among females (67.5%), those who consumed sugar more than six times (77.5%), those who brushed their teeth once per day (80.3%), those who used no dental floss (68.4%), those who did not use mouthwash or rinse (68.4%), and those in the east and center regions (100%). The obese possess a statistically significant (P < 0.05) higher mean dmft/DMFT (dmft = 8.00 and DMFT = 6.00). Furthermore, BMI had a negative influence on the DMFT score (b = −0.01, P = 0.776), which was not statistically significant.

Conclusion

Participants categorized as obese demonstrated a notably higher mean dmft/DMFT in comparison to their non-obese counterparts. Although BMI showed a negative impact on the DMFT score, this association did not reach statistical significance.

Introduction

Dental caries, a multifaceted disease process that alters the plaque biofilm, is caused by a variety of lifestyle factors. This led to several strategies aimed at addressing its root causes [1, 2]. Dental caries is among the most common illnesses globally, far more common than seasonal allergies [3]. For most people, dental caries usually advances gradually over months [3]. Numerous variables, including salivary movement, fluoride exposure, sugary food consumption, and preventive measures like routine dental checkups and cleanings, influence its evolution [4, 5]. Unresolved dental caries in primary teeth disproportionately affected adolescents, impacting approximately 2.4 billion people globally in 2015 [6]. This condition can result in chewing difficulties, speech problems, decreased punctuality at school, and poor grades [7–9]. Furthermore, a recent meta-analytic study reveals that the prevalence of dental caries among children of 5–7 years and 12–15 years was 84% and 72%, respectively, in Saudi Arabia [10].

Childhood and adolescent obesity is a pressing global health concern, showing increasing rates in low- and middle-income nations, as well as persistently high levels in many affluent countries [11]. Early-onset obesity frequently persists into adulthood and is associated with physical (cardiometabolic) and mental health (psychosocial) challenges, as well as premature mortality [12–14]. Providing effective and compassionate care tailored to each child and their family is crucial. In 2019, the World Obesity Federation projected that by 2025, there would be 206 million children and adolescents aged 5–19 years living with obesity, increasing to 254 million by 2030 [11]. Among the 42 countries expected to have over 1 million affected children by 2030, China ranks highest, followed by India, the USA, Indonesia, and Brazil [11].

Bull, Al-Ansari [15] reported a higher prevalence of obesity among children and adolescents globally in 2016 aged 5 to 17 years. This represents a notable rise in prevalence, from 4% in 1975 to 18%. El Mouzan eta al. [16] conducted the statewide research in Saudi Arabia and found that 10.6% of children and adolescents aged 5 to 18 years had obesity and 26.6% were overweight. The earlier research by Al-Hussaini eta al. [17] discovered that the obesity rate among children and adolescents aged 6 to 16 years in Riyadh was 18.2% in 2019. The eastern region of the kingdom had an even greater rate of obesity, at 27.5%. According to Al-Hussaini et al. [17] and Bull eta al. [15], obese children and adolescents aged 5 to 18 years may face some systemic disorders, such as increased blood pressure, decreased tolerance to glucose, respiratory issues, psychosocial abnormalities, and decreased quality of life.

Obesity and dental caries may have long-term negative health effects, including diabetes and cardiovascular disorders [11, 18]. Previous research indicates a positive link between obesity and dental caries [19]. Similarly, de Jong-Lenters, van Dommelen [20] found a correlation between higher body weights and a higher incidence of dental caries in children aged 5 to 8 in the Netherlands. Bailleul et al. [21] reported an association between the mean DMFT and body BMI among severely obese teenagers in France. Ashour et al. [22] also reported a positive connection of obesity with dental caries among female students receiving special education in Saudi Arabia. Nonetheless, there are differing conclusions regarding these relationships [23–27]. As a result, additional research is required to clarify the link between dental caries and obesity.

High rates of dental caries can cause a negative effect on people’s oral health. Similarly, childhood obesity is an alarming epidemic that affects both children’s social and physical development. Several regions in Saudi Arabia evaluated the relationship between obesity rates and dental caries [22, 24]. However, conflicting and inconclusive findings on this topic highlight the need for further exploration into the existing association between dental caries and obesity. Therefore, this study intends to evaluate the possible relationship between obesity and dental caries across the Saudi Arabian region.

Methods

We conducted a survey between January and March 2024, which was a cross-sectional survey in five regions of Saudi Arabia, namely the south, north, east, west, and centre. The cities selected were Sakaka (northern region), Buraidah (central region), Taif (western region), Abha (southern region) and Dammam (eastern region). The dental schools in the mentioned cities have a community outreach program which includes school visits. We used the stratified cluster random selection approach to select the children for this study, who were permanent residents of the respective regions with ages between 6 and 14. We initially selected the schools from a list of schools in each region using a simple random (lottery) process and approached them through the community services programs. We then used a simple random selection procedure to select children from the selected schools, considering the students registered in those schools. Ethical permission was taken from the local committee of bioethics, Jouf University (Approval Number LCBE/07-06-43). Participation was voluntary, both parents and children were informed about the purpose of the study before taking oral and written consent from children and either of the parents. This study excluded children with any psychiatric issues or those with impaired health from participation.

We estimated the study sample using dental caries prevalence based on a previous study [28]. For this survey, the largest computed sample size was selected; sample sizes varied according to the caries prevalence rates for various BMI categories. Considering 95% alpha error and a power of 80%, a sample size of 350 children was obtained and was considered clinically significant to detect a change of 10% regarding the caries prevalence. The final adjusted sample size was estimated to be 390, accounting for the approximate 10% of incorrect data entry and missing values. Furthermore, we obtained both oral and written agreement from parents and children after explaining the study’s goal to them. Participation was entirely voluntary. The study promised to protect the privacy of personal data and only share or publish it as general data.

Two dentists who had received training and calibration performed intraoral examinations on each of the chosen children. Based on the recommended standards for studies related to oral health, we evaluated caries presence by employing the DMFT index of all the dentitions [29]. The deciduous and primary teeth had different scoring of DMFT, which were observed individually. In addition, we determine the inter- and intra-examiner reliability using Kappa. The results showed good to very good agreement, with a range of 0.78–0.82.

We assessed children’s obesity by calculating their BMI, which is obtained by computing the ratio of the child’s weight (kg) to the square of their height measured in meters. We used a stadiometer to measure height and a physician’s scale to record weight. The BMI scores were categorized based on recommended guidelines: a score of less than 18.5 indicates underweight; a score of 18.5–24.99 indicates normal BMI; a score of BMI 25–29 indicates overweight; and a score of 30 and greater indicates obesity [30].

We used a self-reported tool from a previous study [31] to gather data on the participants’ age, gender, lifestyles, and oral hygiene practices (such as tooth brushing, flossing, and mouthwash usage). The frequency of tooth cleaning and daily sugar consumption were quantified. Parents completed a 24-h dietary recall chart twice, with a one-week interval between administrations, to assess their child’s sugar intake. The participant’s sugar consumption was calculated by averaging the data from the two charts. Additionally, twenty parents engaged in face-to-face interviews to assess the questionnaire’s reliability using Cronbach’s alpha, and a value of 0.75 was obtained. This reveals adequate reliability.

Data analysis

Initially, we conducted data cleaning to rectify missing values and erroneous data entries. Version 27 of SPSS was employed for the study statistical analyses. The analyses conducted in the current study were descriptive analysis, student t-test, one-way analysis of variance (ANOVA), as well as linear regression analysis. We used descriptive analysis to present frequencies and percentages. The student t-test along with the ANOVA are performed for determining the significant mean difference in dmft/DMFT scores across the general characteristics of the study participants with two and three categories, respectively. Finally, multiple linear regression analysis was carried out to obtain the significant predictors of the DMFT score (P < 0.05).

Results

Table 1 displays the general characteristics of the participants. There are 380 respondents in all, consisting of females (60.8%) and males (39.2%). Those from the south region (35.3%), overweight (53.4%), and aged 6–10 had the highest proportion (72.6%). The mean age of the respondents was 9.1 years, and their mean BMI was 26.3.

Table 1.

Participant characteristics (n = 380)

Characteristics	N (%)
Gender
Females	231 (60.8)
Males	149 (39.2)
Region
North	63 (16.6)
South	134 (35.3)
East	95 (25.0)
West	31 (8.2)
Centre	57 (15.0)
Age
6	63 (16.6)
7	52 (13.7)
8	43 (11.3)
9	64 (16.8)
10	54 (14.2)
11	31 (8.2)
12	40 (10.5)
13	21 (5.5)
14	12 (3.2)
BMI
Normal	156 (41.1)
Overweight	203 (53.4)
Obese	21 (5.5)
BMI scores	Mean (Range)
Female	26.6 (22.1, 29.0)
Male	25.9 (23.0, 31.1)
Overall	26.3 (22.1, 31.1)

Table 2 displays the mean difference in dmft/DMFT between gender, region, dental practices, and eating habits of respondents. The females possess a higher mean (dmft = 6.17 and DMFT = 4.31) compared to the males (dmft = 6.09 and DMFT = 3.75); nonetheless, the results show non-significance (P = 0.841 and P = 0.198). Those who consumed sugar more than six times show a higher significant mean (dmft = 7.65; P < 0.001; and DMFT = 4.88; P < 0.001). Brushing teeth less than once per day shows a significantly higher mean (dmft = 9.00; P < 0.001; and DMFT = 6.00; P < 0.001). Not using dental floss shows a higher significant mean (dmft = 6.90; P < 0.001; and DMFT = 4.50; P < 0.001). Those who do not use mouthwash had a significantly higher mean dmft/DMFT (dmft = 6.90; P < 0.001; and DMFT = 4.50; P < 0.001). Those from the north show a higher significant mean (dmft = 9.33; P < 0.001), whereas those from the west show a higher significant mean (DMFT = 10.00; P < 0.001).

Table 2.

An evaluation of the participants’ eating patterns, dental caries, and oral hygiene routines

	Mean ± SD		Prevalence of caries (dmft/DMFT ≥ 1)
	Deciduous	Permanent
Sex
Female	6.17 ± 3.67	4.31 ± 3.84	67.5%
Male	6.09 ± 3.89	3.75 ± 4.26	65.1%
Overall	6.14 ± 3.75	4.09 ± 4.01	66.6%
Student t-test	0.20	1.29
P	0.841	0.198
Sugar consumption
2–4 times	0.27 ± 0.45	3.40 ± 4.02	26.7%
4–6 times	3.25 ± 2.00	0.65 ± 0.82	43.6%
> 6 times	7.65 ± 3.00	4.88 ± 4.02	77.5%
F-ratio	186.33	30.23
P	< 0.001	< 0.001
Brush teeth per day
Less than once	9.00 ± 4.05	6.00 ± 6.07	50.0%
Once	6.53 ± 3.39	4.63 ± 3.59	80.3%
Twice	2.61 ± 2.36	0.52 ± 0.50	18.8%
F-ratio	53.71	39.24
P	< 0.001	< 0.001
Dental floss
No	6.90 ± 3.36	4.50 ± 4.10	68.4%
Yes	0.53 ± 0.50	1.00 ± 0.00	53.3%
Student t-test	32.27	15.65
P	< 0.001	< 0.001
Mouthwash/rinsing habit
No	6.90 ± 3.34	4.50 ± 4.10	68.4%
Yes	0.53 ± 0.50	1.00 ± 0.00	53.3%
Student t-test	32.27	15.65
P	< 0.001	< 0.001
Region
North	9.33 ± 3.33	4.00 ± 5.70	33.3%
South	5.25 ± 3.23	3.50 ± 4.06	45.5%
East	7.02 ± 2.93	3.67 ± 2.04	100%
West	5.52 ± 4.46	10.00 ± 0.00	61.3%
Centre	3.58 ± 3.41	3.05 ± 2.30	100%
F-ratio	27.43	23.14
P	< 0.001	< 0.001

In addition, the study found caries prevalence to be 66.6% among the study participants (Table 2), and this prevalence was higher among females (67.5%), those who consumed sugar more than six times (77.5%), those who brushed their teeth once per day (80.3%), those who used no dental floss (68.4%), those who did not use mouthwash or rinse (68.4%), and those in the east and centre regions (100%).

The relationship between dental caries and BMI among study participants is illustrated in Table 3. The obese possess a higher statistically significant mean (dmft = 8.00 and DMFT = 6.00) compared to the normal individuals (dmft = 4.21 and DMFT = 4.53). Additionally, the obese demonstrated a 100% caries prevalence.

Table 3.

The association between dental caries and BMI and among study respondents

	BMI classification			ANOVA
	Normal	Overweight	Obese	F-ratio	P
Mean dmft	4.21 ± 3.33	7.44 ± 3.60	8.00 ± 0.00	43.43	< 0.001
Mean DFMT	4.53 ± 4.68	3.55 ± 3.54	6.00 ± 0.00	5.27	0.006
Caries prevalence	45.5%	79.3%	100%

Table 4 illustrates the factors that significantly predict the DMFT score. The findings reveal that gender (β = 0.20, P < 0.001), participants’ age (β = 0.85, P < 0.001), sugar consumption (β = 0.32, P < 0.001), and region (β = 0.07, P = 0.041) were significant and positively associated with DMFT score. Conversely, tooth brushing frequency per day (β = −0.23, P < 0.001) and mouth wash or rinsing (β = −0.13, P < 0.001) were significant and positively associated with DMFT score. Furthermore, BMI had a negative influence on the DMFT score (b = −0.01, P = 0.776), which was not significant (P = 0.776).

Table 4.

The factors associated with DMFT score

Model-1	β	S.E	β	P	95% CI
(constant)	−14.82	2.12	−	< 0.001	−18.99, −10.65
Gender	1.65	0.239	0.20	< 0.001	1.18, 2.12
Age	1.49	0.056	0.85	< 0.001	1.38, 1.60
Sugar consumption	1.86	0.272	0.32	< 0.001	1.32, 2.39
Brush teeth per day	−1.74	0.241	−0.23	< 0.001	−2.22, −1.27
Mouthwash/rinsing	−1.58	0.447	−0.13	< 0.001	−2.46, −0.70
BMI	−0.02	0.07	−0.01	0.776	−0.15, 0.11
Region	0.22	0.107	0.07	0.041	0.01, 0.43

Discussion

This study investigated how dental caries relates to obesity among children in five different Saudi Arabian regions between the ages of 6 and 14. The literature has advocated for a probable indirect biological relationship between dental caries and obesity, given that unhealthy eating patterns and improper diets not only encourage obesity but also foster an environment that is conducive to the growth of dental caries, particularly when sugary foods are consumed in excess [11, 28]. However, because of its challenging nature, more study and research are required to confirm this relationship. Furthermore, as children’s oral health span provides chances to make behavior adjustments that may shape behaviors that persist into adulthood, focusing on children’s health is critical in order to achieve the objectives related to public health programs [32].

The current study reports a caries prevalence of 66.6%, which is lower than the 76.1% reported by Khattak et al. [31] and Al-Ansari and Nazir [23] (79.8%), and closely aligns with findings from a prior study among 10–12-year-old schoolchildren in Dammam, where the caries prevalence was 68% [33]. The relatively lower caries prevalence discovered could be related to numerous factors, such as diverse geographic origins amongst our participants, disparities in study demographics and sample size, as well as potential shifts in caries trends over time. This finding emphasizes the necessity for holistic and unified approaches to caries management, adopting the common caries risk factors and obesity risk factors.

The current study found that obesity was prevalent at 5.5%. The Riyadh survey by Al-Ansari and Nazir [23] found a substantially higher prevalence, with 18% of male teenagers classified as obese. However, previous research on obesity and caries in Jeddah revealed that up to 24% of youths were obese [26]. Similarly, 30% of 12-year-old grade 6 pupils were categorized as obese by Madinah’s research [34]. Nonetheless, the National Health Profile Project data revealed that Saudi Arabia had a 9.3% national obesity prevalence among teenagers [16]. Differences in the measures used to define obesity may be the cause of disparities in prevalence estimates across the nation. For example, different organizations used different cutoff values [16, 23].

Brushing teeth less frequently shows higher mean dmft and DMFT than brushing teeth once daily, consuming sweets greater than six times a day, and not using mouthwash or dental floss. This finding is consistent with previous studies conducted by Ashour et al. [22], Chaudhary et al. [35], Farooqi et al. [33], and Khattak et al. [31], which discovered a link between inconsistent brushing practices and an increased rate of dental caries. Conversely, the Khattak et al. [31] study highlighted no significant relationship between participants’ dental floss and mouthwash routines regarding mean dmft or DMFT scores. Similarly, Ashour et al. [22] found that people who consumed sugar possess a higher rate of dental caries when compared to people with no sugar consumption. Significant changes in Saudi Arabians’ dietary and lifestyle habits over the last thirty years have led to a decrease in health-related practices, such as the intake of high-fat meals [36].

In this study, individuals classified as obese in comparison to the non-obese exhibited a significantly higher mean dmft/DMFT. This outcome mirrors the results of the Khattak et al. [31] study, which also indicated a higher mean dmft/DMFT among obese individuals, although in their study, only DMFT showed statistical significance. Although the study’s findings indicate that being overweight is strongly associated with the occurrence of dental caries, the relationship between BMI and caries in the literature is still debatable. These findings are consistent with a previous systematic review study [37]. Prior research conducted in Saudi Arabia in the Al-Khobar region found similar findings about the relationship between obesity and caries experience [23]. Nonetheless, the cross-sectional study by Ravelomantsoa et al. [38] reveals a strong link between caries and increased BMI.

The study demonstrates that individuals residing in the east and center regions had a higher caries prevalence, with those from the north and west regions having the highest mean dmft and DMFT values, respectively. We believed that this study is the first to attempt evaluating the caries prevalence and its association with obesity across various regions in Saudi Arabia. A recent study reported that the prevalence of dental caries among children of 5–7 years and 12–15 years was 84% and 72%, respectively, in Saudi Arabia [10]. According to Al Agili [39], children who attend public preschools are more likely to have caries, which also tends to increase in prevalence and severity with age. The prevalence might reach 94% by the time a child reaches 9 years old [39].

The study findings reveal that age and sugar consumption are significantly and positively associated with the DMFT score. Conversely, the frequency of daily tooth brushing, mouthwash use, and mouthwash or rinse usage reveals a strong negative correlation with the DMFT score. The following are popular instances of behaviourally adjustable risk variables that negatively affect dental caries and obesity: age, increased sugar intake, regularity of brushing teeth, and rinsing or mouthwash usage [31, 37, 40, 41]. As a result, studies related to dental caries and obesity must take these variables into account in order to implement coordinated, integrated approaches for preventing them both locally and globally. This finding raises some possibilities that identifying and treating risk factors related to obesity and dental caries requires a comprehensive as well as coordinated approach to caries management. Children with special needs should have their dental and general health given priority in this kind of approach.

Furthermore, the study found a negative but non-significant relationship between respondents’ BMI and dental caries. Few studies [31, 42, 43] reported a negative relationship between caries and BMI. Given that eating processed carbohydrates and sweet foods promotes the chances of acquiring dental caries and obesity, past literature emphasizes how difficult it is to understand the mechanism underlying this unfavourable relationship [43]. Obese people’s eating habits could be one plausible explanation for this inverse connection. Instead of eating a diet heavy in sugar and refined carbohydrates, people who are obese typically consume a diet higher in fatty, fried, and unprocessed carbs [31, 34, 43]. This eating pattern can contribute to obesity [36]. However, BMI could have a strong relationship with dental caries that is stable in the permanent dentition as opposed to primary dentition [36]. Other studies, on the other hand, have illustrated that caries may be positively influenced by BMI. Even though the prevalence of dental caries and obesity often heightens with advancing age [23, 31, 41], there is a tendency for this link to get stronger with age.

The research faced several limitations. We collected data from public schools, which cautions against broad generalizations of the study results. The study employs a cross-sectional survey, which may present some challenges when establishing a causal relationship, leaving room for alternative explanations for the observed associations. Additionally, the potential for recall bias in food history could have influenced the study results.

Conclusion

Participants identified as obese in this study showed a significantly greater mean DMFT compared to those who were not obese. We discovered that DMFT scores were highly influenced by age, increasing sugar intake, frequency of daily tooth brushing, and usage of mouthwash or rinsing. Furthermore, although BMI had a negative effect on the DMFT score, this association did not reach statistical significance.

Author contributions

Conception OR design of the work: MAA, OK. Acquisition, analysis, OR interpretation of data: MAA, HAA, SHA, MNSA. Drafted the work or substantively revised it: MAA, OK, AI. Approved the submitted version: HAA, MNSA, SHA, AI.

Funding

This research is funded by the Deanship of Graduate Studies and Scientific Research at Jouf University through the FastTrack Research Funding program.

Data availability

All data included in this study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Ethical approval was taken from the local committee of bioethics, Jouf University (Approval Number LCBE/07-06-43) Saudi Arabia. Informed consent to participate was obtained from the parents or legal guardians of participants under the age of 14.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.