Mothers are the main source of passing streptococci mutans, the bacteria responsible for causing caries, to their infants. However, any caregiver can be a potential source of transmission.
Transmission occurs via saliva contact such as tasting or pre-chewing food.
If mom's bacterial level is high, transmission is more likely.
Transmission can occur even before the first teeth erupt at about 6 months of age.
Evidence suggests that babies born by caesarean delivery are more likely to have early acquisition of S. mutans. This is possibly due to decreased exposure to maternal microorganisms during birth, which can compete for colonization in the predentate environment.
If colonization is delayed until after age two, then the child will have fewer caries.
Caregivers with caries also often pass on bad habits (high sugar intake, poor oral hygiene).
Message to moms should be BRUSH FOR TWO!
Bacterial transfer can occur via shared utensils
De Abreu da Silva Bastos, V, Freitas-Fernandes, LB, et al. Mother-to-Child Transmission of Streptococcus Mutans: A Systematic Review and Meta-Analysis. Journal of Dentistry 43 (2015) 181-191.
Finlayson, TL, Gupta A, et al. Prenatal Maternal Factors, Intergenerational Transmission of Disease, and Child Oral Health Outcomes. Dent Clin N Am 61 (2017) 483-518.