Association between Body Mass Index and Decayed, Missing, and Filled Teeth (DMFT) in 12-year-old School Children

1. INTRODUCTION

The body mass index (BMI) is a tool used to determine whether a person's weight is proportional to their height. It is calculated by dividing weight in kilograms by the square of height in meters (kg/m²). In children and adolescents, BMI values are interpreted based on age and sex. BMI measurement provides a critical perspective on health and well-being of a human body, as deviations from expected values can indicate significant impacts on growth, quality of life, and overall health in children.

Dental caries, an infectious oral disease characterized by the demineralization of tooth tissue, has a prevalence exceeding 80%. Globally, it is estimated that 3.5 billion people are affected by oral diseases. Caries is particularly common among children, regardless of socioeconomic background or dietary habits [1-3].

Studies highlight the public health importance of oral hygiene and nutrition due to their significant impact on overall health and well-being. As a result, these topics remain a focal point for health professionals [4]. In a study conducted in Mexico City, it was determined that the majority of people who were examined had dental caries, with a prevalence of 91%. In contrast, 14.5% of the population was affected by overweight or obesity. Interestingly, women were the most affected by these conditions [5]. The prevalence of caries in the same country is shown as one of the highest, with a study conducted between 2010 and 2019 reporting a rate of 94.5%. From 2020 to 2021, this figure decreased to 88.5%. Dental caries is clearly linked to various biological, behavioral, and socioeconomic factors [2]. In a 2022 study in Ecuador, Mena Paola et al. estimated that caries outcomes were directly related to the body mass index (BMI). This finding confirmed the complex relationship between dental caries and obesity, suggesting that dental caries were linked to the habits children develop throughout their lives [6].

Research in Brazil, of a similar nature, has shown that malnutrition is linked to dental caries among low-income children. The study found that 60% of these children had decayed teeth and a higher-than-average PUFA index [7]. While the direct association between BMI and DMFT in children remains inconclusive in some studies, associations have been found that suggest an influence on disease predisposition. These results highlight the potential for policy interventions in oral care and nutritional development to improve child health [2-9].

The DMFT index in a community indicates an average of the individual sum of decayed, missing, and filled teeth, classifying them into different stages according to their severity: very low (0 to 1.1), low (1.2 to 2.6), moderate (2.7 to 4.4), high (4.5 to 6.5), and very high severity (6.6 or >6.6) [10].

The present study aims to answer the following question: is there a correlation between BMI and DMFT in 12-year-old school children in the Bellavista-Cuenca parish? This is a topic that has not been extensively studied in the local context. The study involves forming an association by collecting data from the specified area to evaluate the relationship between BMI and DMFT in 12-year-old school children in the parish of Bellavista-Cuenca.

2. MATERIALS AND METHODS

The present study is observational with a quantitative approach since the dental caries index (DMFT) and its association with the body mass index (BMI) were determined using a data collection technique based on cards. This study was carried out between 2023 and 2024 on schoolchildren in Ecuador, in the city of Cuenca, parish Bellavista. The research complies with the bioethical approval and confidentiality norms. The institutional ethics committee approved the study for research on the Catholic University of Cuenca whose code is CEISH - UCACUE- 013, issued on May 18, 2023, and the legal representatives were duly informed of the study. The study corresponded to all 12-year-old schoolchildren in the different educational units belonging to the Bellavista parish of the canton of Cuenca in Ecuador, and different public schools with morning and afternoon sections, where it was possible to collect complete data on the population studied.

3. RESULTS

During the years 2023 and 2024, 458 schoolchildren from various schools in the Bellavista sector were examined, with data collection carried out in two stages: one at the end of the school year and the other at the beginning of the school year and categorized by the sex of the 458 schoolchildren, data of 32 students were lost because some children changed schools, and others decided not to continue, and some schoolchildren over the age of 12 no longer met the criteria for inclusion in the study. Finally, the research focused on 426 children with complete information, classified by gender. The mean BMI for the entire sample was 20.91 (SD = 4.2), and the mean DMFT score was 2.44 (SD = 2.3). Among the BMI categories, very underweight individuals had a DMFT score of 2.88 (SD = 1.73), underweight individuals had a DMFT score of 2.83 (SD = 2.42), and normal-weight individuals had a DMFT score of 2.69 (SD = 2.43). Overweight individuals showed a DMFT score of 2.37 (SD = 2.37), while obese individuals were the least affected, with a DMFT score of 2.00 (SD = 1.98).

Table 2 shows the different nutritional levels classified according to the WHO. This reflects that in the female group, according to nutritional status, the risk of being overweight in women is more prevalent at 28.5% than in men; this group is more prevalent at the overweight level with 28.2%.

The results indicate that there is no difference at the DMFT level between male and female children as shown in the statistical test X²p= 0.3934 (Table 3).

There is no significant association between DMFT levels and nutrition levels, as reflected in the Fisher-Freeman-Halton exact test p= 0.648. The same occurs when evaluating this association in each sex group (Table 4).

Fig. (1) illustrates a trend where higher BMI levels correspond to higher DMFT levels, while lower DMFT levels are observed at healthier BMI levels. Conversely, the highest levels of caries experience tend to cluster at the extremes of BMI.

4. DISCUSSION

The study was carried out in the urban area of Cuenca, Ecuador. Previously, there was no study conducted of this type in this region. The BMI index given by the WHO was used for both males and females with an average age of 12 years due to the stage of completion of tooth replacement and the DMFT index, in addition to the fact that the WHO follows this age to use indexes, make international comparisons and carry out epidemiological surveillance in oral health. This result is similar to a study carried out in Mexico in 2020, where in children from 8 to 12 years of age who had obesity, the risk of caries was not that high, however, children without obesity had the highest caries risk because they were daily consumers of sugar [15].

On the other hand, in Saudi Arabia in the year 2020, they introduced in their research the association between obesity and dental caries in children between 12 and 15 years old, since they are known to be global health problems. In their study, they observed that children with high caries belonged to the obesity group; it was more prevalent in males than in females. In the present study, the prevalence of caries according to DMFT also shows an inclination for the male sex. Therefore, it is understood that preventive policies should be taken into account to control these diseases [16].

In many countries, caries is a neglected problem. Therefore, there are always high prevalence reported in some studies. The DMFT index of 12-year-old children recorded in the year 2021 in the study by Olivan Gonzalo et al. showed that in Ecuadorian children residing in Spain, untreated caries was more prevalent with 25.4% in comparison with children of other nationalities. Also, there is no direct association of the nutritional status with the BMI [17].

On the other hand, according to a study in Mexico in 2014, an association between caries and body mass index dental caries was higher in school children who were overweight and obese [18]. Likewise, in the same country, another study was conducted in the year 2023 where a population of children from an area in the east of the country was studied, and the data highlighted in the same way an association between DMFT and BMI in the two groups having both male and female children affecting the level of obesity, however the DMFT index was presented only in the male group, that is where the importance of adequate information on nutrition, promotion and prevention programs in schools guiding to new eating habits and likewise avoiding caries is reflected [19].

In El Salvador, a study conducted in 2022 by Salgero Jennifer et al., who investigated the association of body mass index with the caries index, lost and filled, and reported that there was a direct association between them. This research was conducted in mixed dentition, the results indicated that in the permanent dentition, the prevalence of caries was 70, 5% and the caries index in primary dentition was 94.9%. This finding related to the BMI was prevalent in children in the overweight and obese group. This number indicates that more prevention and information on general and oral health should be instilled in the population of this country [20].

Mohajeri Amir et al. examined in their study the correlation between obesity and dental caries using regression models considering demographic variables, socioeconomic status, diet, and controlling factors. However, the data indicated that caries and untreated caries were not directly related to BMI-weight, therefore, there are other external causes involved, such as poor hygiene, family habits, etc. It is indicated that dentists should be aware of these factors since they greatly influence the development and prevention of caries [21]. Shi Rou et al. conducted a study in China, investigating dietary habits, hygiene habits, and parental status. The found that BMI and DMFT were negatively related; the underweight group had the highest prevalence with 65.6% than the obese group with 41.1% prevalence of caries [22].

In the study carried out by the government of Cameroon in 2023, in a cross-sectional investigation, six hundred and fifty school children from different primary schools were evaluated. It was revealed that the prevalence of overweight was very high, and the oral pathology that was most related was dental caries, with 60.3%. This meant that overweight children were 1.5 times more likely to develop caries. In our research, we found contradictory results. The analyzed results did not correlate with our findings as children who were overweight did not have any caries [23]. It is well known that nutrition significantly impacts oral health, which is why there are multiple studies analyzing the possible factors, perhaps to plan new strategies. A study conducted in Turkey was similar to our study; however, its study population was 5 to 14 years of age; after all the results were analyzed, it was shown that obesity was a pretty prominent risk factor, and the risk of caries increased in this group of school children examined [24]. Therefore, these two variables had a direct association, which differed from what was found in the present study [25], and the DMFT index is under constant debate. Some studies suggest that the higher the BMI, the greater the experience of dental caries. However, in the study conducted in Iraq, caries-free individuals and patients with caries were from the normal weight group. This differs from the present study, which found that the caries-free children (with very low DMFT level) belonged to the overweight (+2DS) and obese (+3DS) groups [26-28].

Ali Borzabadi et al., identified a possible relationship between malocclusion and caries, with no significant association overall, but in certain subgroups [29]. In another study by the same author, they noted that caries increases with age and is more prevalent in men. Our study, although without significant associations, highlights the importance of a multifactorial approach considering different age groups [30].

On the other hand, another study in Saudi Arabia has reported contradictory results, showing that obese children may have higher DMFT values. These findings suggest that the relationship between obesity and caries is multifactorial and may be influenced by other factors such as age, gender, oral hygiene habits, and diet. It is essential to continue exploring this association in different population settings and with more precise methodologies to better understand the interaction between oral health and nutritional status [31, 32].

The study by F. Eslamipour suggests that obesity may be related to poorer oral hygiene, increasing the risk of caries. Although our study did not find a significant association between BMI and caries, it showed a trend of higher caries with lower BMIs. Both studies highlight that this relationship is multifactorial and should be evaluated considering hygiene, diet, and socioeconomic status, reinforcing the need for a preventive and comprehensive approach [33].

CONCLUSION

According to the analysis of 426 school children from the parish of Bellavista-Cuenca, there was no statistically significant association found between the body mass index (BMI) and DMFT index. This relationship was not reflected in the Fisher-Freeman-Halton test and was maintained even when analysing the data by sex. However, the mean values of the DMFT index tend to be centred at the extremes of BMI, showing a greater experience of caries in both underweight and highly underweight school children. At the same time, the lowest levels of DMFT were recorded in children with obesity. These trends do not have statistical significance but may indicate a non-linear relationship or multifactorial influence useful for future studies.

REFERENCES