What do systematic reviews say?

Down syndrome vs Individuals without Down syndrome (healthy controls: siblings, schoolchildren or others)

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.

• Association between Dental Caries and Down Syndrome: A Systematic Review and Meta-Analysis. 2015 All outcomes

  Individuals with and without Down syndrome from referral centres, national databases and schools across China, Portugal, Jordan, Nigeria, Brazil and India; cross-sectional studies
  SMD -0.18 [-0.35, -0.02]
  6 studies · 718 participants
  GRADE not reported

Down syndrome vs Individuals without Down syndrome (healthy controls: siblings, schoolchildren or others)

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.

• Association between Dental Caries and Down Syndrome: A Systematic Review and Meta-Analysis. 2015 All outcomes

  Individuals with and without Down syndrome in Portugal (reference centre, national database and closest-age siblings); cross-sectional studies
  OR 0.36 [0.22, 0.57]
  2 studies · 314 participants
  GRADE not reported

Down syndrome vs Healthy controls

Gingivitis prevalence was 65.4% in children with Down syndrome versus 70.4% in controls.

• Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. 2021 All outcomes

  Children with Down syndrome
  Prevalence 65.4
  1 study
  GRADE not reported

Down syndrome vs Healthy controls

Dental caries prevalence was 57.6% in children with Down syndrome and controls.

• Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. 2021 All outcomes

  Children with Down syndrome
  Prevalence 57.6
  1 study
  GRADE not reported

Down syndrome vs Healthy controls

Dental erosion prevalence was 34% in children with Down syndrome versus 15.3% in controls.

• Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. 2021 All outcomes

  Children with Down syndrome
  Prevalence 34
  1 study
  GRADE not reported

Down syndrome vs Healthy controls

Mean DMFT was 2.73 in children with Down syndrome versus 1.65 in controls.

• Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. 2021 All outcomes

  Children with Down syndrome
  MEAN 2.73
  1 study
  GRADE not reported

Down syndrome (oral health status) vs Healthy controls

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).

• Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. 2021 All outcomes

  Dubai, UAE
  Ghaith et al. (Dubai) reported dental decay in 57.6% of children with Down syndrome (same as controls) but a higher mean DMFT (2.73 vs 1.65) and calculus index (0.25 vs 0.07), higher erosion prevalence/severity, and…
  1 study
  GRADE not reported

Disability (developmental, intellectual, or sensory) vs Persons without disabilities

Persons with disabilities in Saudi Arabia report poorer overall oral health-related quality of life and greater oral-health impact than those without disabilities, synthesized narratively without a pooled estimate (ungraded).

• Disabilities and Disparities in Oral Health-Related Quality of Life: A Systematic Review and Meta-Analysis in Saudi… 2024 All outcomes

  Cross-sectional · Autism centres, dental hospital, disability centres, hospital, and public schools across Saudi Arabia (Riyadh, Jeddah, Qassim, Abha)
  Narrative synthesis (no pooled estimate). PWDs reported reduced functional, emotional, and social well-being and greater oral-health impact on quality of life. AlJameel 2021 (Down syndrome): 34.9% of children and 46%…
  Studies not reported
  GRADE not reported

Disability (developmental, intellectual, or sensory) vs Persons without disabilities

Dental caries prevalence and severity are high among persons with disabilities in Saudi Arabia (60% to over 80%), and the one comparative autism study reported significantly higher caries than controls; synthesized narratively (ungraded).

• Disabilities and Disparities in Oral Health-Related Quality of Life: A Systematic Review and Meta-Analysis in Saudi… 2024 All outcomes

  Cross-sectional · Autism centres and dental/hospital settings in Saudi Arabia (Riyadh, Jeddah)
  Narrative synthesis (no pooled estimate). High dental caries burden among PWDs: caries prevalence 60% to over 80% (abstract). Alkahtani 2019 (hearing-impaired adults, single-arm): caries prevalence 82.2%, treatment…
  Studies not reported
  GRADE not reported

Disability (developmental, intellectual, or sensory) vs Not applicable (single-group prevalence)

Gingival inflammation is common among persons with disabilities in Saudi Arabia (moderate-to-severe up to about 60%), reported narratively without a pooled comparative estimate (ungraded).

• Disabilities and Disparities in Oral Health-Related Quality of Life: A Systematic Review and Meta-Analysis in Saudi… 2024 All outcomes

  Cross-sectional · Hearing-impairment and cerebral-palsy clinical settings in Saudi Arabia (Riyadh)
  Narrative synthesis (no pooled estimate). Moderate-to-severe gingival inflammation up to about 60% among PWDs (abstract). Alkahtani 2019 (hearing-impaired adults, single-arm): 60.1% had moderate gingival inflammation…
  Studies not reported
  GRADE not reported

Toothpaste with a plaque-disclosing agent vs Conventional toothpaste

• Oral hygiene interventions for people with intellectual disabilities 2019 · Cochrane All outcomes

  Short term (<6 weeks)
  Toothpaste with a plaque-disclosing agent vs conventional toothpaste, children with Down syndrome. Ainamo & Bay Gingival Bleeding Index, mean 10 days; percent mean difference 18 (intervention) vs 8 (control), P<0.001…
  1 study · 40 participants
  Very low

Toothpaste with a plaque-disclosing agent vs Conventional toothpaste

• Oral hygiene interventions for people with intellectual disabilities 2019 · Cochrane All outcomes

  Short term (<6 weeks)
  Simplified Green & Vermillion Oral Hygiene Index (plaque), mean 10 days; percent mean difference 65 (intervention) vs 15 (control), P<0.0001 favouring the disclosing-agent toothpaste; 40 participants (SoF states 80,…
  1 study · 40 participants
  Very low