Prevalence of early childhood caries in 8 - 48 month old preschool children of Bangalore city, South India.

Early Childhood Caries (ECC) is a devastating form of dental decay having a multi - factorial origin. This study was undertaken to determine the prevalence of ECC in Bangalore city, South India, and also to study its associated risk factors. Random sample of 1500 children, aged between 8 - 48 months, was selected from play homes and nursing homes of various parts of the city. Dental caries was recorded according to World Health Organization criteria. Information regarding risk factors for caries was obtained through a structured questionnaire given to mothers or caretakers. The data was subjected to statistical analysis. The prevalence of ECC was 27.5% and the mean decayed, extracted and filled tooth index was 0.854. There was a strong association of ECC with the risk factors studied.

Introduction

Early Childhood Caries (ECC) is a complex disease which involves maxillary primary incisors within a month after eruption and spreads rapidly to involve the other primary teeth, causing serious socio - behavioural and dental problem in infants and toddlers.[12]- Despite the major advances in the field of caries prevention over the past few decades, there are still reports of high caries prevalence in young children.[3]

Early Childhood Caries is a multi - factorial disease[2] that involves a susceptible tooth and host, fermentable carbohydrates in the diet, cariogenic micro - organisms and time.[4] Oral biology may be modified by several factors unique to young children such as the immaturity of the host defense system, the behavioral patterns associated with feeding and oral hygiene in early childhood. The scope and severity of the problem appear to vary with cultural, genetic and socio - economic differences within a community.

Bangalore is a rapidly growing metropolitan city of South India, with children from different socio - economic and cultural backgrounds. The present study aimed to determine the prevalence of ECC in 8 - 48 month old children of Bangalore city, and its association with factors such as chronological age, birth weight, family income, educational status of the mother, feeding habits and oral hygiene practices.

Materials and Methods

There is no comprehensive data available on the population of children, aged 8 - 48 months in Bangalore city. Hence the sample size was calculated according to the WHO guidelines for estimating a population proportion and sample size to attain results with specific relative precision,.[5] The anticipated population proportion (P) was computed or chosen to be 50%, at 95% confidence level with a relative precision (α) of 5%.[5] The sample size was estimated to be 1537 children. Ethical clearance to conduct the study was obtained from the institutional review board. Permission was taken from the authorities of crèches, nurseries, child day care centers, kindergartens and nursing homes or clinics in different parts of Bangalore city, from where the children were selected. The parents/caregivers of children attending these play schools and nursing homes were informed of the nature of the investigation. Prior to examination of the children, written consent was obtained from them. They were given a questionnaire which required information pertaining to the child's chronological age, birth weight, family income, educational status of mother, feeding habits and oral hygiene practices. However, parents/caregivers of 37 children did not complete the questionnaire and thus 1500 children aged 8 - 48 months formed the sample size for the study.

A prior schedule for data collection was prepared, and an average of 10 children was examined per day. The children were seated on a chair during the examination. The knee - to - knee examination method was also utilized in the case of very young children.[6] Oral examination was performed by a sole examiner using disposable mouth mirrors and torch light. The WHO criteria were followed to diagnose caries.[7] The community periodontal index (CPI) probe was used to confirm visual evidence of caries on the occlusal, buccal and lingual surfaces. Training and calibration for examination of dental caries was carried out in the Department Pedodontics and Preventive Dentistry, The Oxford Dental College and Research Centre, Bangalore. Caries was recorded by a dental surgeon sitting besides the examiner, so that the codes given by the examiner could be easily heard. In each school, two children were examined twice for intra - examiner reliability. The kappa value for intra - examiner agreement of the tooth status was 0.88.

Data was analyzed using the Statistical Package for Social Sciences (SPSS), Version 11.0 computer software package. Chi - square tests were used for the comparison of proportions. Multivariate logistic regressions analysis was done to determine the correlation between ECC and risk factors studied.

Results

Of the 1500 children examined, the prevalence of caries was seen in 413 children (27.5%) with mean decayed, extracted and filled tooth index (deft) of 0.854 [Graph 1]. The increase in the prevalence of caries was linear with age and was statistically significant. Children aged 44 - 48 months showed a higher caries prevalence of 37.2% [Graph 2]. Twenty seven percent of the 499 children with low birth weight (< 2500 gm) were affected with early childhood caries [Graph 3]. Of the 422 children with parents having an annual income of more than $4000, only 71 children (16.8%) had caries. This was found to be lower when compared to 214 (34%) of the 618 children whose parents had an annual income of less than $1000. A statistically significant correlation was found between caries prevalence and low family income [Graph 3]. Thirty eight percent of the children, whose mothers had no schooling, had caries. This was statistically significant when compared to those children whose mothers had higher education, and in whom the caries prevalence was low (22%) [Graph 4].

Graph 1

Prevalence of Early Childhood Caries in the children included in the study

Graph 2

Prevalence of Early Childhood Caries in the children included in the study in relation to Age

Graph 3

Prevalence of early childhood caries in the children in the study according to birth weight of child and annual Family income

Graph 4

Prevalence of early childhood caries in children included in the study according to educational status of mother

With regard to feeding habits, 450 children (30%) were wholly breast fed, 191 (12.7%) were exclusively bottle fed, and 859 (57.2%) children had been fed by both methods. Though caries prevalence of breast fed children was marginally higher (29.6%), method of feeding did not show any significant relation with caries prevalence. A significant percentage (30%) of children who were breast fed on demand had caries. Children who were bottle fed at night were also affected significantly. Pacifiers were used by 184 children and only 26% of them had caries. Of the children for whom pacifiers were used, 76 children used it after dipping it in honey or sugar solution, and 22 of them children had caries. Almost 77% of children consumed snacks between meals. A statistically significant correlation was found between caries prevalence and consumption of in - between meal snacks. Twenty seven percent of the 539 children who received nutritional supplements in the form of calcium, vitamins, iron or fluorides had caries whereas, 36% of the children who were not given any nutritional supplements had caries, which was highly significant [Table 1].

Table 1

Prevalence of early childhood caries in the children included in the study according to their feeding habits

Fifty four percent of children brushed their teeth under parental supervision, 285 (19%) children brushed independently without supervision and 401 (26.7%) children had their teeth cleaned by the mothers/caregivers. Caries was significantly higher in children who brushed without supervision. Although 1159 (77.2%) children went to bed without cleaning/brushing their teeth, only a low number of them (27.7%) had caries. Most children (1050) in this study brushed their teeth only once a day, and nearly 35% of them had caries, which was highly significant. Three hundred and seventy eight (25.9%) children used a fluoridated dentifrice, 1080 (74%) used a non - fluoridated dentifrice, and 42 (2.8%) did not use any dentifrice as an aid in tooth brushing or cleaning. A significantly lower percentage (18.3%) of children who used a fluoride dentifrice had caries. Most of the mothers/caregivers (652) had initiated tooth cleaning by 1 year of age. In 544 (36.2%) children tooth brushing/cleaning was started between 13 - 18 months; in 205 (13.6%) children it was started between 19 - 24 months; and, in 99 (6.6%) children it was started only after 24 months of age. 1342 (89.5%) children used a baby toothbrush, 116 (7.7%) children used their finger and in 42 (2.8%) children, a soft cloth was used to clean the teeth. Of the 1087 children who were caries free, a highly significant percentage of them (88%) used a baby toothbrush. Also, caries was not seen in children who used a soft cloth for cleaning the teeth [Table 2].

Table 2

Prevalence of early childhood caries in the children included in the study according to oral hygiene habits

Multivariate logistic regression analysis showed the correlation of ECC with the associated risk factors. It was observed that ECC was more likely to occur in males and also with increasing age. Children who were breast fed on demand, bottle fed at night and those who consumed between meals snacks were observed to be more affected with ECC. Usage of non - fluoridated toothpaste was positively associated with ECC [Table 3].

Table 3

Multivariate logistic regression analysis to correlate early childhood caries in the children included in the study with associated risk factors

Discussion

In the present study, the prevalence of ECC in Bangalore city was 27.5% with a mean deft of 0.854. In 1987, a similar study on pre - school children of Bangalore showed caries prevalence to be 66.3% with a mean deft of 2.9.[8] This shows a decreased trend of caries prevalence in Bangalore from 1987 to 2007. There has been rapid growth and enormous development in the city of Bangalore not only in area, but also in terms of education, awareness and employment opportunities. The low prevalence observed in our study could be due to the increased availability and use of fluoridated toothpastes, together with increased oral hygiene awareness. Another contributing factor is the large number of dental schools and dental clinics mushrooming in and around the city. The dental schools offer dental treatment at a low cost, thus making them more accessible to families belonging to a lower socio - economical status. These institutions also attempt to educate and motivate the community by conducting various oral health programmes.

It has also been established that Streptococci mutans can be found in the mouth as early as 6 months of age; even prior to tooth eruption.[9] In the presence of ideal predisposing conditions, carious lesions can be initiated within a relatively short period of time after tooth eruption, and can rapidly progress to cavitation.[2] In this study, only one child in the 8 - 13 month old age group was affected with caries. This could be due to the lesser number of erupted teeth in this age group. As in accordance with other studies,[1011] caries prevalence was seen to increase significantly with age. As children grow older, change in their dietary habits and oral hygiene practices pose a greater cariogenic challenge. Although, studies have reported on a significant association between low birth weight and caries[1213] we did not observe the same. However, it should be noted that the number of low birth weight children examined in our study differed from the number of normal birth weight children.

Individuals from lower economic strata experience financial, social and material disadvantages that could compromise their ability to care for themselves, affect their ability to obtain professional oral health care services and live in a healthy environment. All of this leads to a reduced resistance to oral and other diseases.[2] As reported in earlier studies,[211] lower caries prevalence was seen in children from ‘higher income’ families. Low income affects the degree of education, health, values, life styles and access to health care information, thereby increasing susceptibility to caries.[14] Mother is the primary caregiver for the child; and, children whose mothers had no schooling, had significantly higher caries. This finding is similar to other studies which showed a strong association between the mothers’ education and caries experience.[21516] Low levels of maternal education contributes to lack of information and education about the child's oral health care.[17] It has also been observed that motivating an uneducated mother to engage in preventive programmes is a difficult task.[2]

Improper feeding patterns are also responsible for an increased exposure of primary teeth to fermentable carbohydrates. This is likely to promote early colonization as well as increase the number of Streptococci mutans in the dental plaque and saliva. In our study, the caries prevalence was marginally higher in exclusively breast - fed children. While breast feeding presents immunological, nutritional and psychological advantages, prolonged breast feeding seems to be related to dental diseases.[18] Although breast milk is non - cariogenic, it does contain lactose which can be used by cariogenic bacteria to produce acids. A significantly higher number of children who were breast fed on - demand had caries. Ad libitum breastfeeding or breastfeeding for longer duration decreases the plaque pH, and thereby increases the risk of ECC. Therefore, it is essential to wean the child by the first birthday.[19]

In this study, a significantly higher percentage (40.7%) of children, who were bottle - fed at night showed caries. This finding supports the hypothesis that inappropriate bottle feeding behavior increases the risk of caries development rather than bottle - feeding itself.[20 – 22] The decreased salivary flow and swallow reflex during sleep reduces the oral clearance, which is a determinant in caries initiation. In the present study, decreased use of pacifier could be due to an increased awareness of its harmful effects. There was no significant difference in caries prevalence between children using pacifiers, with or without sweeteners. These findings suggest that other factors such as inappropriate feeding habits and poor oral hygiene practices may be more significant in the etiology of ECC than pacifier use alone. The present study supports earlier studies which state that frequent consumption of foods, snacks and drinks in - between meals increases the risk for caries.[1823] There was a significant association between carious lesions and consumption of in - between meal snacks. Hence, limiting snacking time together with an emphasis on the quality of snacks is essential. Diet counseling should include foods rich in antioxidants.

Nutritional supplements and dietary factors have a profound and lasting effect on the developing and developed dentition. Studies have shown that nutritional supplementation is one of the effective strategies for prevention and control of dental caries.[2425] Even in our study, children who were on nutritional supplements had lesser caries. This suggests that a cautious nutritional supplement dosage schedule could be used in children to prevent dental caries. Preschool children do not understand or have the manual dexterity to maintain good oral hygiene. Parental assistance and guidance is essential to reduce the risk of developing caries. This is also evident in our study, where children who brushed alone had significantly higher caries than those children who brushed under parental supervision. There is a need for prolonged parental participation in the cleaning of preschool children's teeth.

Tsai et al., reported low caries prevalence when children brushed at night.[26] However, no significant relation was observed in our study between caries prevalence and brushing at night. This could be due to some mothers feeding their children during the night and not necessarily cleaning the teeth after every feed.

In comparison to those who brushed more frequently, children who brushed only once a day had significantly higher caries prevalence. This suggests that tooth brushing with a frequency of at least twice a day under parental guidance may spare the teeth from developing caries.[12] Fluoride is presently the corner stone of dentifrice anti - caries therapy. Tooth - brushing with fluoridated dentifrice has played a major role in the decline of caries worldwide. This study showed that a significantly lower number of children who used fluoridated dentifrice had caries. Although the caries preventive efficacy of fluoride dentifrice in children has been well documented, the impact of dentifrice use and the total fluoride intake in preschool children must be considered.

Most children in the present study received the benefit of oral hygiene practice by their first year. As reported earlier, there was only a marginal increase in the caries prevalence of those children in whom initiation of tooth brushing/cleaning was delayed.[2728] The soft brush is preferable for most young children because of the lesser likelihood of gingival tissue trauma and increased inter - proximal cleaning ability.[19] Similarly, we observed that a significantly lesser number of children who used a baby brush had caries.

Data obtained from this study can serve as a base line for planning effective caries prevention methods and oral health promotion programmes.

Conclusions

From the results of this study, it can be concluded that:

The caries prevalence in the preschool children of Bangalore city, South India was 27.5%, with a mean deft of 0.854.

Caries significantly increased with age.

Caries was significantly higher in children whose parents belonged to families with low income.

Low maternal education was significantly associated to higher caries prevalence.

Caries was significantly higher in children who were breast fed on demand or bottle fed at night. A significant association was found between caries and consumption of in - between meal snacks. Also, those children who were given nutritional supplements had significantly lower caries.

Increased frequency of tooth brushing, parental involvement, use of a baby tooth brush and fluoridated dentifrice showed significantly lesser caries prevalence.