Nonnutritive Sucking Habits & Occlusal Effects in Mixed Dentition

🎯 3-5-7 Rule for Duration & Risk

  • Stop by 3 → Minimal risk
  • Stop after 5 → Moderate risk (AOB, PXB start appearing)
  • Stop after 7 → High risk (Multiple malocclusions likely)

🍼 Pacifier vs. 👍 Digit — Think “Short vs. Strong”

  • Pacifier = Short habit (≈14 mo), causes AOB + Class II if ≥4 yrs
  • Digit = Strong persistence (≈33 mo), causes AOB if ≥5 yrs

Risk by Habit Duration (Any Habit)

DurationAnterior Open BitePosterior Crossbite≥4 mm OverjetBilateral Class II≥1 Malocclusion
< 36 mo4%9%29%29%53%
36–59 mo12%18%28%29%51%
≥ 60 mo27%20%40%39%76%

Pacifier vs. Digit Habit Impact

FeaturePacifierDigit
Typical DurationShorter (mean ~14 mo)Longer (mean ~33 mo)
Strongest Malocclusion LinkAOB & Class II molarAOB (≥60 mo)
Arch Form ImpactNarrower maxillary arch; occasional PXBLess arch narrowing, but more vertical changes

Quick Statistics for Parent Communication

  • Digit ≥60 mo → 26% have AOB despite habit cessation.
  • Over 50% of mixed dentition children show ≥1 malocclusion.
  • AOB prevalence jumps from 4% (<36 mo) to 27% (≥60 mo).
  • Pacifier ≥48 mo → 54% have Class II molars.

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