This cross-sectional study was conducted in three different areas – one tribal (Amrita Kripa hospital at Kalpetta), one rural (Primary Health Centre at Angamaly) and one urban location (Amrita Institute of Medical Sciences, Cochin) in Kerala, India. These areas were chosen based on availability of health centers, and to account for different socioeconomic status. The ethical clearance was obtained from Institutional review board of Amrita Institute of Medical Sciences, Kochi, India. We enrolled children attending the health care center for vaccination or medical reasons in each of the three locations. Written informed consent was obtained from the parent(s) or guardian(s) of children involved in the study.

A structured close-ended questionnaire was used, which had information related to socioeconomic status of parents, health status of the child, prenatal history and drug history of the mother, feeding practices, and milestones of development. Dental caries was assessed by use of a plain mouth mirror with a light source with the child seated on a chair or on lap of mother.　Presence of any decayed, extracted or filled teeth were considered as evidence of ECC, and Deft index was recorded [11]. Weight was assessed using digital scale with 100 g increments. Nutritional status was assessed using the WHO growth curve for children up to five years of age. Children who had weight-for-age between 25th　and 75th percentiles were considered normally nourished.　Those children who did not have adequate weight for age were classified into two groups: (i) Borderline undernutrition (between 5th　and 25th　percentile) and (ii) undernutrition (below 5th　percentile). To assess the association of ECC with nutritional status for adjusting the potential confounders, multivariate analysis was performed using SPSS version 17.

We enrolled 550 (186 tribal, 184 rural and 180 urban) children (age 8-60 mo) in the study.　　Table I shows the association of the various covariates with ECC.　　 The frequency of the ECC increased with lower categories of nutritional status.　　The children classified as having normal nutritional status had the lowest (22.3%) (Mean (SD) deft score and undernutrition 0.93 (1.73) prevalence of ECC compared to those with borderline undernutrition [33.2% (mean (SD) deft score 2.22 (2.92) and 44.5% (mean (SD) Deft score 3.4 (3.23)], respectively. In multivariate analysis model, the association of ECC with nutritional status persisted after adjustment for potential confounders (Table II).

TABLE I  Association of Early Childhood Caries With Various Risk Factors

TABLE II	Multivariate Logistic Regression of Factors Associated with Early Childhood Caries 

In this study, we found that undernutrition of the preschool child was associated with ECC. The children who had borderline undernutrition had twice the odds of having ECC whereas children having undernutrition had thrice the odds of having ECC, when compared to children with normal nutritional status. These findings were consistent with other studies [5-7].

As the study was hospital-based, it may have selection bias. Temporality of the causal relationship of ECC and undernutrition, which has complex interaction with other covariates, is difficult to establish in cross-sectional methodology.　　 Use of non-standard definitions of undernutrition is another limitation of this study. The preschool children were selected from three different geographical areas covering various socioeconomic conditions to strengthen the external validity of the study.

The study findings of higher dental caries scores in undernourished children are comparable with other studies [9,10]. There are various plausible mechanisms for association of dental caries with underweight and poor growth in young children [8]. First, untreated caries and associated infection can cause pain and discomfort and reduce intake of foods because eating becomes painful [8]. Second, dental caries can cause disorders of appetite and sleep, which affects the overall growth of the child [8]. Disturbed sleep may affect glucosteroid production and growth. Chronic inflammation from pulpitis and dental abscesses affects metabolic pathways involving cytokines [12]. It has been shown that child tends to catch-up the growth within six months following　rehabilitation of ECC, and shift to higher　growth percentiles categories [10].　

　Early childhood caries is a morbid condition that is difficult to treat in infants and very young children. ECC has received little attention from the health professionals other than dentists. Physicians treating young children should consider that ECC is a risk marker for undernutrition. For physicians, nutritional deficiencies should alert them to the possibility that ECC is present and is a possible explanation for the deficiencies in their patients. For dentists, children presenting with ECC should be considered at-risk for nutritional deficiencies that may affect long-term health and well-being.

Contributors: CJ: study concept, design of the study, critical review and manuscript writing; BA: data analysis, data-collection, drafting of the manuscript, and critical revision of the manuscript for important intellectual content; JJ: critical revision of the manuscript for important intellectual content, design of the study.

Funding: Amrita Vishwa Vidhyapeetham, Kochi India;

Competing interest: None stated

1. Kuriakose S, Prasannan M, Remya KC, Kurian J, Sreejith KR. Prevalence of early childhood caries among preschool children in Trivandrum and its association with various risk factors. Contemp Clin Dent. 2015;61:69-73.

2. Priyadarshini HR, Hiremath SS, Puranik M, Rudresh SM, Nagaratnamma T. Prevalence of early childhood caries among preschool children of low socioeconomic status in Bangalore city, India. J Int Soc Prev Community Dent. 2011;1:27-30.

3. Prakash P, Subramaniam P, Durgesh BH, Konde S. Prevalence of early childhood caries and associated risk factors in preschool children of urban Bangalore, India: A cross-sectional study. Eur J Dent. 2012;6:141-52.

4. Jose B, King NM. Early childhood caries lesions in preschool children in Kerala, India. Pediatr Dent. 2003;25:594-600.

5. Retnakumari N, Cyriac G. Childhood caries as influenced by maternal and child characteristics in pre-school children of Kerala-an epidemiological study. Contemp Clin Dent. 2012;3:2-8.

6 Duijster D, Sheiham A, Hobdell M, Itchon G, Monse B. Associations between oral health-related impacts and rate of weight gain after extraction of pulpally involved teeth in underweight preschool Filipino children. BMC Public Health. 2013:13:533.

7. Malek Mohammadi T, Wright CM, Kay EJ. Childhood growth and dental caries. Community Dent Health. 2009;26:38-42.

8. Sheiham A. Dental caries affects body weight, growth and quality of life in pre-school children. Br Dent J. 2006;201:625-6.

9 Clarke M, Locker D, Berall G, Pencharz P, Kenny DJ, Judd P. Malnourishment in a population of young children with severe early childhood caries. Pediatr Dent. 2006; 28: 254-9.

10. Sheller B, Churchill SS, Williams BJ, Davidson B. Body mass index of children with severe early childhood caries. Pediatr Dent. 2009;31:216-21.

11. Shankar S, Naveen N, Kruthika M, Vinay S, Shaikh H. Comparison of Deft index with Nyvad’s new caries diagnostic criteria among three to six years old children in a school at Bangalore city. Indian J Dent Res. 2012;23: 135-9.