Dental caries a complex chronic disease of multifactorial etiology that affects a children worldwide. Its risk factors include a susceptible tooth, fermentable sugars and caries bacteria. Certain upstream factors have also been implicated in the etiology of dental caries and they are those that promote a favorable oral environment for dental caries susceptibility and progression. One of such upstream factors is prenatal smoking. The prenatal period is a sensitive time for fetal growth and development, including the development of the primary tooth germ that commences at the end of the 5th week of gestation. Exposure to prenatal smoking during this critical period not only affects the health and wellbeing of the developing fetus but also the quality of the developing tooth. Previous studies that have found an association between prenatal smoking and dental caries in the child relied on self-reported smoking during pregnancy, and thus, susceptible misreporting and recall bias of actual smoking status. This current study utilizes an objective measure of exposure to smoking in-utero in the form of newborn DNA methylation (DNAm) measured in cord blood collected at birth.