Associations of nutritional status and oral health-related quality of life with early childhood caries of children aged 4–5 years: a hospital-based cross-sectional analytical study

Regular growth and development during early childhood can be hindered by different communicable diseases and chronic severe early childhood caries (S-ECC). Comprehensive studies on the factors associated with ECC, nutritional status, and oral health-related quality of life (OHRQoL) are scarce. Thus, this study aimed to investigate dietary, oral hygiene, and socio-demographic factors associated with these conditions and their impact on OHRQoL in a hospital-based cohort of Sri Lankan children. This cross-sectional analytical study included 545 children aged 4–5 years attending the Pedodontic Clinic at the Dental Teaching Hospital, University of Peradeniya, Sri Lanka. After obtaining parental consent, data were collected using a pre-validated questionnaire, and oral examinations were conducted by three trained and calibrated dentists. Binary logistic regression analysis and negative binomial regression analysis were used to examine the effects of independent variables on nutritional status, ECC status, and OHRQoL. Within this clinical sample, higher S-ECC severity assessed via the defs index and the consumption of some sugary snacks and sweets were significantly associated with poor nutritional status ( P < 0.05). Conversely, higher weight-for-age, BMI-for-age, and maternal education levels were significantly associated with a lower likelihood of S-ECC. Adverse dietary habits (frequent consumption of sweetened snacks), prolonged breastfeeding (> 2 years), bottle-feeding, and inadequate oral hygiene practices (infrequent or unsupervised brushing and use of non-fluoridated toothpaste) were identified as key behavioral indicators significantly associated with increased S-ECC ( P < 0.05). Furthermore, lower nutritional status and higher defs indices were strongly associated with poorer OHRQoL scores ( P < 0.001). S-ECC and poor nutrition were prevalent among 4-5-year-olds, strongly associated with dietary habits, oral hygiene practices, and maternal education, while both conditions correlated with lower oral health-related quality of life. Importantly, higher ECC and poor nutrition were interrelated, highlighting the potential utility of integrated oral health and nutritional interventions in clinical pediatric settings.