Babies who suck their thumbs or use pacifiers are more likely to grow up with crooked teeth. But breastfed babies may be more likely to develop a nicer smile.
Domenico Viggiano, MD, and colleagues studied about 1,000 preschool children aged 3-5 in the southern Italian town of Cava de' Tirreni. The kids had all participated in an oral health study organized by the local school.
Data included how the children were fed during their first three months of life and whether any children had used pacifiers or sucked their thumbs for more than one year, which the researchers call "non-nutritive sucking."
A dentist examined all the children's teeth to flag any flaws in their mouths.
The researchers found that breastfeeding appeared to have a "protective effect" against posterior cross-bite, which occurs when the top back teeth bite inside the bottom back teeth.
Bottle-fed children accounted for 11% of cross-bite cases, compared with 4% of breastfed kids.