This study aimed to assess the relationship of dietary patterns, such as frequency, timing, and cariogenicity of food/beverage consumption, with plaque acidogenicity and early childhood caries (ECC) in Japan. A total of 118 children aged 1–4 years who had visited the pediatric dental clinic were enrolled. We retrospectively reviewed their records to collect data including age, sex, medical history, medication, caries status, and plaque acidogenicity level at the first dental visit. The plaque acidogenicity level was measured using Cariostat®. Dietary data were collected from 3-day dietary records, and the dietary cariogenicity score was calculated from these data. Children with ECC or high plaque acidogenicity consumed between-meal sugars more frequently than did their counterparts (p = 0.002 and p = 0.006, respectively). Children with ECC or high plaque acidogenicity drank juices between meals more frequently than at mealtimes (p = 0.02). Frequent consumption of between-meal sugars was associated with higher plaque acidogenicity and ECC, and frequent breast/bottle feeding was associated with ECC. No differences were found in the dietary cariogenicity scores between these groups. Therefore, the frequency and timing of sugar consumption, might affect plaque acidogenicity and ECC, and reducing the frequency of sugar intake could prevent ECC.

This study examines the cross-cultural validity of the Japanese version of the Food Frequency Questionnaire (FFQ), designed for studies on dental caries to assess dietary intake in Japanese children. Parent-reported dietary data were collected (274 children, 3–6 years old) using the 38-item FFQ, whose reliability and validity have been demonstrated in adults. Factor analysis was used to determine dimensionality. Dietary cariogenicity scores were compared with the levels of plaque mutans streptococci, and the decayed, missing, and filled teeth (dmft) index to evaluate the criterion validity using Pearson’s correlation coefficient (r) and the Kruskal–Wallis test. The FFQ showed good criterion validity, assessed through its relationship with the dmft index (r = 0.119; p = 0.05) and Dentocult SM score (r = 0.124; p = 0.04). Factor analysis revealed six questionnaire subscales. Internal consistency was from low to acceptable (Cronbach’s alpha = 0.64 for the total scale, 0.39–0.53 for each subscale). Children with a higher SM score were more likely to have higher dietary cariogenicity scores (p = 0.01; Kruskal–Wallis test). These results confirm the validity of the Japanese version of the FFQ for children, which can be used to track dietary structure dynamics regarding cariogenicity from childhood to adulthood.