A Study to Explore the Relationship between Dental Caries and Weight of the Slum Living Children in Dhaka

*Corresponding Author: Dr. Mahfujul Haq Khan, Professor & Head, Department of Dental Surgery, BIRDEM General Hospital, Unit Head and BDS

Being the capital of the country, Dhaka is over populated having a large number of slum dwellers where dental caries has not spared these under privileged people.In most cases dental decay remains untreated here 1,2 which affects the growth and wellbeing of millions of children 3 .Dental decay become more painful in case of children because they can not verbalize the feeling of pain like adult.The immaturity of children, developing cognition and dependency on adults influence the interpretation of pain.And this creates a problem when the need for treatment is assessed.It does not only cause pain and discomfort, but also in addition, places a financial burden on parents of the affected children.
Socio-economically deprived people do not heed that much attention to the dental problems of their children because they find the dental treatment to be very expensive.A previous study conducted in the slum areas of Tongi, Dhaka reported that, the mean DMFT is higher in both male and female than that of the urban people 4 .Moreover, poor people are mostly not able to provide healthy and nutritious food to their children.Due to their poor socio-economic status and low purchasing power they can not provide their children appropriate food rich in animal protein, vitamins and minerals which are required for their growth.Lack of healthy diet causes severe deficiency of vitamin-D which further increases the risk of demineralization and causes dental caries 5 .
Nutritional deficiencies in the growing child, whether due to deprivation, overindulgence or malabsorption syndromes may have significant impact on neural development and somatic growth 6 .Dental caries is the most prevalent oral disease and it remains the single most common disease of childhood that is not amenable to short-term pharmacological management 7 .Most of the dental decay remains untreated with significant impacts on general health, quality of life, development and educational performance.So once it is developed it begins to unveil its various symptoms which hamper the normal dietary habit, psychological status, sleeping pattern, social interaction thus ultimately hamper the normal growth of children.Different theories explain the relationship between dental decay and child's growth.Study has shown that untreated dental caries affects the normal eating habit of the children and thus hampers their nutritional intake 8,9 .Poor nutritional intake can also increase the susceptibility to caries due to altered saliva composition and secretion 10 .Moreover severe infection makes the children unable to sleep which ultimately affect their normal growth 11 .Infected dental pulp may affect the immune system and erythropoiesis [12][13][14][15] of children which in turn may cause anemia 14 and also hamper the bone remodeling 16,17 .It is also reported that, severe underweight children with dental caries gain weight rapidly and their quality of life were improved after the treatment of dental caries 11 .Bangladesh is a low income country with a lot of children suffering from malnutrition and poor health, especially among the deprived sectors of the population.Dental caries is a common phenomenon among the children in Bangladesh which is more significant among the socio-economically poor people.The country has very limited facilities for dental treatment and a high population to dental service provider ratio (100,000/2) 18 .But it is alarming that the nutritional and carious status are deteriorating day by day which ultimately may become responsible for the retardation of growth of the children of slum dwellers in Dhaka city.So the objective of our study was to explore the association of being under-weight and dental caries among the slum living children in Dhaka which will further help us to plan comprehensive dental preventive programs and facilitate those children to have sound oral and dental health.

Methods:
A cross sectional study was conducted among 310 children in a slum area at Pallabi, Mirpur in November, 2015.A simple random sampling technique was used to design the study in case of selecting sampling unit (the children).Data collection included dental clinical examination, anthropometric measurements and a questionnaire comprised of 15 questions related to their age, sex, height, weight.For the socio-economic status the parents of those children were asked some questions regarding their occupation, education, salary, sanitation etc.And to record their nutritional status and dietary habit the children were asked some questions regarding the protein, carbohydrate, vitamins intake.
The children were interviewed by two dentists and the dental clinical examination was performed by another two dentists according to the standard procedures explained by World Health Organization (WHO) 19 .All the anthropometric measurements were done according to the standard guidelines 20 .All the children stood upright without wearing their shoes and the height was measured with a portable stadiometer to the nearest 0.5 cm.The weight was measured with a portable electronic digital scale to the nearest 0.5 kg.Height and weight were assessed by using the z scores of height for age (HAZ), weight for age (WAZ) and BMZ 21 .
The deviation of height, weight and BMI for specific age and gender from the international standard was calculated automatically by using WHO AnthroPlus Software 22 .
Oral examinations were performed by using caries probe, mouth mirror, torch, disposable gloves and masks.Teeth were dried prior to the examination using cotton pellets.Teeth were examined in natural day light and torch was also used for proper visibility.It was not considered to be a dental decay or caries when the ball ended probe did not enter into the cavitations as they were considered as initial stage of cavitations.

Statistical Analysis:
The data were coded and analyzed by SPSS (Statistical Package for Social Sciences) software version 20.0.A level of P ≤ 0.05 was considered statistically significant and P ≤ 0.001 was taken as highly statistically significant.The children were divided into three age groups (below 6 years, 7-12 years and above 12 years).An analysis was done to assess the relationship between all the variables for children with any decayed teeth and underweight children.For each group we assessed a dichotomous association between being underweight and having at least one decayed tooth.
We constructed a series of linear regression models for each age group to assess the association between each of the two main outcomes (weight for-age z-score and height-for-age z-score) and number of untreated caries adjusting for sex.At last, we assess the relationship between being underweight (weight-for-age z-scores < −2) and having at least one untreated decayed tooth, adjusting for sex by using logistic regression.

Discussion:
This study revealed a robust inverse relationship between dental decay and weight among slum living children of Dhaka.In this study the height for age and weight for age were adversely related to the dental decay.We can also observe the similar pattern of relationship between dental caries and growth in the previous studies conducted in developing countries 23,24 .
Dental caries affects the growth in different manners.It alters the eating ability, sleeping quality and thus hampers the daily activities of children which ultimately cause retardation of their growth.Many studies have shown the inverse relationship between caries and growth especially in case of body height and weight.
In our study we have seen that, children who had caries in one or more teeth were significantly more likely to be underweight (weight-for-age) at the age group of below 6 years and 7-12 years.Other studies have also demonstrated that there is no association between dental caries and obesity.Granville-Garcia et al 25 observed the association between caries in obese and non-obese children in Brazil and found no relationship between obesity and caries while they also assessed a significant relationship between caries and not being obese.But it was difficult to find out whether the non-obese children were normal or under-weight due to their improper categorization.A significant association was also found between dmft and BMI in a Turkish study 26 of similar age group.This linear inverse relationship was found in an Australian longitudinal study 27 .Furthermore, a Swedish study 28 showed the relationship between different categories of BMI and untreated caries.This unavoidable relationship is confounded by a lot of conditions.Different environmental, social and economical conditions affect the oral health that further play an important role in retardation of growth 29 .Poor nutritional status is commonly seen among the people of poor socio-economic status.Poor diet is responsible for various diseases including dental decay or caries.Different studies have shown the relationship between dental caries and socio-economic status.Study has shown that the higher prevalence of dental caries is more likely to be seen in poor socioeconomic division 30 .A study 31