Cross-sectional study of the factors associated with the number of teeth in middle-aged and older persons with intellectual disabilities.
Level 4 - case-series / case-control
Cross-sectional survey study
PubMed 35929423 · doi:10.1111/jir.12967
What was done
A cross-sectional questionnaire survey on oral health was administered to 604 individuals over 40 years of age with intellectual disabilities in Aichi Prefecture, Japan. Information was collected via proxy reports on disability diagnosis, disability severity, residence type, proxy-reported tooth count (categorized as ≥20, 10–19, or 0–9), regular dental check-ups, and tooth-brushing frequency. Multinomial logistic regression and linear regression models were used to analyze factors associated with tooth count.
What was found
Having 0–9 teeth (versus ≥20) was significantly associated with Down syndrome compared to intellectual disability alone (OR 3.17, 95% CI 1.09–9.23), not attending regular dental check-ups (OR 2.37, 95% CI 1.06–5.30), and brushing once daily compared with ≥3 times daily (OR 4.76, 95% CI 1.09–20.77). In multivariate linear regression, tooth count decreased by 0.42 teeth per year of age, was 0.74 higher in autism spectrum disorder, 0.93 lower in Down syndrome, and 2.12 lower among participants without regular dental check-ups.
Why it matters
The study highlights modifiable risk factors (regular check-ups and brushing frequency) and high-risk groups (such as individuals with Down syndrome) for tooth loss in aging adults with intellectual disabilities.
Limits
The cross-sectional design cannot establish causality. Tooth counts and oral health habits were proxy-reported rather than clinically verified by dental examinations, risking reporting bias. The sample was drawn from a single geographic prefecture.
Cited by
- partial Individuals with Down syndrome are frequently rendered edentulous by their 30s.