Gingivitis prevalence was 65.4% in children with Down syndrome versus 70.4% in controls.
Dental caries prevalence was 57.6% in children with Down syndrome and controls.
Dental erosion prevalence was 34% in children with Down syndrome versus 15.3% in controls.
Mean DMFT was 2.73 in children with Down syndrome versus 1.65 in controls.
Individuals with Down syndrome had a lower mean DMFT in permanent teeth than controls (pooled SMD -0.18, 95% CI -0.35 to -0.02; 6 studies; I2=20%); certainty of evidence not graded.
Individuals with Down syndrome had a lower prevalence of dental caries than those without (pooled OR 0.36, 95% CI 0.22 to 0.57; 2 studies; I2=0%); certainty of evidence not graded.
One study found children with Down syndrome had similar caries prevalence but higher DMFT, calculus, erosion and malocclusion than controls, with better restorative-care access (narrative synthesis; not GRADE-rated).