Related Experiment Video
Updated: Oct 15, 2025

Micro-dissection of Enamel Organ from Mandibular Incisor of Rats Exposed to Environmental Toxicants
Published on: March 29, 2018
Being Left Alone at Home and Dental Caries of Children Aged 6-7 Years
Yusuke Matsuyama1, Aya Isumi1,2, Satomi Doi1,2
1Department of Global Health Promotion, Tokyo Medical and Dental University.
Background:
Leaving children alone at home is considered child neglect in some countries but is not prohibited in Japan. We investigated the association between being left alone at home and dental caries of children aged 6-7 years in Japan.
Methods:
The data on first graders in all 69 public elementary schools in Adachi, Tokyo, obtained from repeated cross-sectional surveys in 2015, 2017, and 2019 were analyzed. Caregivers answered the questionnaire, and the data were linked to the information on children's dental caries evaluated in school dental health checkups (N = 12,029). Poisson regression analysis with propensity score matching (PSM) was applied to account for confounders.
Results:
Leaving children alone at home for ≥1 hour during the weekdays was reported by 46.4% of the caregivers, which did not vary across years. The PSM analysis showed that, compared with children never being left alone at home, children being left alone at home for ≥1 time per week had more dental caries (mean ratio [MR] 1.11; 95% confidence interval (CI), 1.02-1.21; P = 0.016), while <1 time per week was not associated (MR 0.97; 95% CI, 0.92-1.03; P = 0.345). The difference between those being left alone at home for <1 time per week and those being left alone for ≥1 time per week was not significant after applying Bonferroni correction (MR 1.12; 95% CI, 1.00-1.26; P = 0.041).
Conclusion:
Leaving children alone at home for ≥1 hour every week might be a risk factor for dental caries of children aged 6-7 years.
Related Concept Videos
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
Oral Cavity
Teeth: The teeth are the hardest structures in our bodies. Humans have two sets of teeth throughout their lifetime: deciduous (baby) teeth and permanent teeth. Each tooth consists of several parts: the crown (visible part), the root (embedded in the jaw), enamel (hard outer...
Relationship with Parents: Attachment
Psychosexual Stages of Personality: Oral
Weaning, typically occurring...
Relationship with Other Adult Family Members and Siblings

