A large study of over 71,000 Japanese children found that toddlers who increased their screen time to one hour or more daily by age 3 had significantly higher rates of tooth decay and cavities compared to those with minimal screen exposure, suggesting that reducing screen time during meals and toothbrushing routines may help prevent early childhood tooth decay.
- Toddlers who went from no screen time at 18 months to one or more hours daily by age 3 had 27% higher odds of developing cavities.
- Children with persistent high screen exposure showed a 55% greater risk of severe tooth decay compared to low-exposure peers.
- The study analyzed data from 71,438 children in Japan using routine health check-up records and dental assessments
- Screen-free meals and toothbrushing routines are recommended strategies to reduce cavity risk in young children.
Children who had no regular screen time at 18 months old but watched an hour or more daily by age 3 had greater odds of developing caries by that age, according to a large study recently published in Pediatrics and Neonatology.
Additionally, these children had the highest risk of multiple dental problems, including severe caries and caries counts, the authors wrote.
“Trajectory-based monitoring at toddler health checks may support counseling to keep meals and toothbrushing screen-free,” wrote the authors, led by Dr. Toshifumi Yodoshi, PhD, of the Cincinnati Children’s Hospital Medical Center in OH (Pediatrics and Neonatology, October 7, 2026).
During children’s early years, their screen habits can change quickly. Unhealthy dietary habits, shorter sleep, and worse oral health have been associated with excessive sedentary screen time in preschoolers. However, it is unclear if screen exposure has an effect on caries in younger children.
In 2025, a study revealed that factors including unhealthy lifestyles and problematic internet use may significantly increase the risk of caries in children. Furthermore, making small changes, like having appropriate bedtimes and reducing screen time, may help prevent tooth decay in children.
To determine whether there was a correlation between screen time and caries in children, the researchers analyzed data from the routine child health check-up records of 71,438 children ages 18 months to 3 years old in Japan. At their 3-year checkups, caregivers reported a child's routine screen time per day, and dentists assessed them for caries, according to the study.
Multivariable logistic regression estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI).
Children between 18 months old and 3 years who newly exceeded one hour of daily screen time had greater odds of dental caries at age 3 than those who maintained low exposure (aOR 1.27; 95% CI, 1.12 to 1.45). Also, persistently high exposure was linked to tooth decay (1.11; 95% CI, 1.02 to 1.20), the authors wrote.
Also, these pediatric patients had the strongest odds of developing severe caries (aOR 1.55; 95% CI, 1.31 to 1.84) and caries counts (incidence rate ratio 1.29; 95% CI, 1.14 to 1.46), they wrote.
Despite the strengths of this study, including its large sample size and population-based design leveraging a high-coverage health checkup system, it also had limitations. Caregivers reported screen time for their children, the authors wrote.
“Incorporating trajectory-based screening and repeated counseling into toddler health checks may help prevent early childhood caries while supporting screen-free routines around meals and oral hygiene,” Yodoshi wrote.
