What do systematic reviews say?

Extraction of the primary maxillary canine plus cervical pull headgear vs no intervention

• Extraction of primary (baby) teeth for unerupted palatally displaced permanent canine teeth in children 2012 · Cochrane All outcomes

  At least 6 months follow-up after the intervention
  Narrative (not pooled, not GRADE-rated). Leonardi 2004: successful eruption 80% with extraction plus cervical pull headgear, significantly higher than the untreated control group (Chi2 14.9; P<0.01). Baccetti 2008: the…
  2 studies · 81 participants
  GRADE not reported

Extraction of the primary maxillary canine plus cervical pull headgear vs Extraction of the primary maxillary canine alone

• Extraction of primary (baby) teeth for unerupted palatally displaced permanent canine teeth in children 2012 · Cochrane All outcomes

  At least 6 months follow-up after the intervention
  Narrative (not pooled, not GRADE-rated). Leonardi 2004: extraction plus headgear (80%) gave significantly higher eruption than extraction alone (50%) (Chi2 4.69; P<0.05). Baccetti 2008: extraction plus headgear was…
  2 studies · 79 participants
  GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Non-linear positive dose-response: little change in overall fracture risk below ~1.5 mg/L drinking-water fluoride, with risk increasing above that threshold (RR 1.06, 1.19, 1.35 at 2.0, 3.0, 4.0 mg/L vs null); ungraded (4 studies).

• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 1.2 mg/L vs null
  RR 1.00 [0.80, 1.24]
  4 studies
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 4.0 mg/L vs null
  RR 1.35 [0.94, 1.95]
  4 studies
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 3.0 mg/L vs null
  RR 1.19 [0.87, 1.64]
  4 studies
  GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Femoral-fracture risk was mildly U-shaped: RR 0.86 at 0.5 mg/L rising to 1.06 at 1.8 mg/L drinking-water fluoride vs null; risk mostly below null across the range; ungraded.

• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 1.8 mg/L vs null
  RR 1.06 [0.67, 1.69]
  Studies not reported
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 0.5 mg/L vs null
  RR 0.86 [0.71, 1.05]
  Studies not reported
  GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Fragility-fracture risk overall was slightly U-shaped: RR 0.93 up to 0.9 mg/L, ~1.00 at 1.48 mg/L, 1.05 at 1.8 mg/L drinking-water fluoride vs null; ungraded.

• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride up to 0.9 mg/L vs null
  RR 0.93 [0.84, 1.02]
  Studies not reported
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 1.8 mg/L vs null
  RR 1.05 [0.82, 1.35]
  Studies not reported
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Sensitivity (excluding high risk-of-bias studies): 0.8-1.5 mg/L vs null
  RR 0.93 [0.72, 1.21]
  Studies not reported
  GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Spine BMD showed an inverted U-shaped association with fluoride (peak ~0.6 mg/L); excluding high risk-of-bias studies gave small positive MDs (e.g., 0.05 g/cm2, 95% CI 0.01-0.10, up to 2.27 mg/L); ungraded.

• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Sensitivity (excluding high risk-of-bias studies): 1.27 to 2.27 mg/L vs null
  MD 0.05 [0.01, 0.10]
  Studies not reported
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Sensitivity (excluding high risk-of-bias studies): 0.60 mg/L vs null
  MD 0.06 [-0.02, 0.13]
  Studies not reported
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Both sexes, main dose-response
  Inverted U-shaped association in both males and females, highest value around 0.6 mg/L (no numeric MD reported in text for main analysis)
  Studies not reported
  GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Hip BMD increased with fluoride in both sexes (linearly in males, non-linearly above ~1.2 mg/L in females); no numeric MD reported in text for the main analysis; ungraded.

• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Both sexes, main dose-response
  Hip BMD increased in both sexes, linearly in males and non-linearly (starting above 1.2 mg/L) in females (no numeric MD reported in text for main analysis)
  Studies not reported
  GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Wrist-fracture risk declined nearly linearly with increasing fluoride: RR 1.00 at 0.01 mg/L to 0.84 at 1.5 mg/L drinking-water fluoride vs null; ungraded.

• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 1.5 mg/L vs null
  RR 0.84 [0.43, 1.65]
  Studies not reported
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 0.01 mg/L vs null
  RR 1.00 [0.99, 1.01]
  Studies not reported
  GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Overall hip-fracture risk showed little association with drinking-water fluoride and a nearly flat dose-response curve (narrow CI); no numeric RR reported in text; ungraded.

• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Overall dose-response (0 to highest exposure)
  Curve indicated little association and was nearly flat, with a comparatively narrow 95% confidence band (no numeric RR reported in text)
  Studies not reported
  GRADE not reported