REVIEW A systematic review of risk factors during first year of life for early childhood caries PAMELA MARGARET LEONG 1,2 *, MARK GREGORY GUSSY 3 , SU-YAN L. BARROW 4 , ANDREA DE SILVA-SANIGORSKI 1,5 & ELIZABETH WATERS 1 1 Jack Brockoff Child Health & Wellbeing Program & McCaughey Centre, School Population Health, University of Melbourne, Carlton, Vic., Australia, 2 Department of Dentistry, Royal Children’s Hospital, Parkville, Vic., 3 Department of Dentistry & Oral Health, La Trobe Rural Health School, La Trobe University, Bendigo, Vic., 4 Melbourne Dental School, University of Melbourne, Carlton, Vic., and 5 Dental Health Services Victoria, Melbourne, Vic., Australia International Journal of Paediatric Dentistry 2013; 23: 235–250 Background. Early childhood caries (ECC) describes dental caries affecting children aged 0–71 months. Current research suggests ECC has important aetio- logical bases during the first year of life. Gaps in knowledge about disease progression prevent the effective and early identification of ‘at risk’ children. Aim. To conduct a systematic review of research studies focusing on (a) acquisition and coloniza- tion of oral bacteria and ECC and (b) risk and/or protective factors in infants aged 0–12 months. Design. Ovid Medline and Embase databases (1996–2011) were searched for RCT, longitudinal, cross-sectional and qualitative studies. Two inves- tigators undertook a quality assessment for risk of bias. Results. Inclusion criteria were met for (a) by four papers and for (b) by 13 papers; five papers were rated medium or high quality. Bacterial acquisi- tion/colonization and modifying factor interrela- tionships were identified, but their role in the caries process was not clarified. Key risk indicators were infant feeding practices (nine papers), mater- nal circumstances and oral health (6) and infant- related oral health behaviours (4). Conclusion. This review confirmed that factors occurring during the first year of life affect ECC experience. Despite heterogeneity, findings indi- cated maternal factors influence bacterial acquisi- tion, whereas colonization was mediated by oral health behaviours and practices and feeding habits. Introduction Early childhood caries (ECC) describes dental caries affecting children 71 months of age or younger 1 . Studies in nonindustrialized and industrialized countries have reported caries prevalence in very young children to vary between 28% and 82% 2–6 depending on the population studied. There are few Australian studies reporting caries prevalence in infants and preschool-aged children with most Aus- tralian data coming from school-aged chil- dren 7, 8 accessing the public school dental services in each state. This data indicate that 47% of 5- to 6-year-old children have cavi- tated carious lesions, and of these lesions, 80% are active and untreated 9 . A recent Aus- tralian study estimated that 45% of hospital ‘oral cavity’ admissions for children aged <2 years of age were related to dental car- ies 10 . It is important to understand the natu- ral history of ECC in order to implement effective preventive strategies. Prevention and early intervention are critical as children with ECC may experience pain and infection of dental origin and exhibit poor sleeping pat- terns, altered eating habits and behaviour, poor self-esteem 11 , reduced speech produc- tion and communication skills, low body weight and height 12 and failure to thrive 13, 14 . Furthermore, ECC is a strong predictor of dental caries experience in later life 15 . Although ECC is recognized as multifactoral in nature, there are gaps in our knowledge as Correspondence to: Pamela Margaret Leong, Department of Dentistry, Royal Children’s Hospital, Parkville, 50 Flemington Road, Vic., 3052 Australia. E-mail: pamandyin@gmail.com © 2012 John Wiley & Sons Ltd, BSPD and IAPD 235 DOI: 10.1111/j.1365-263X.2012.01260.x