Pediatric Dentistry · single question
Down syndrome is a contraindication for use of which of the following in dental management?
Show answer and explanation
Correct answer: A. Nitrous oxide
Patients with Down syndrome have a high prevalence of atlanto-axial instability (AAI) — laxity of the ligaments between C1 and C2 due to hypotonia. Nitrous oxide (N2O) requires the patient to keep their head still in certain positions, and N2O can cause muscle relaxation that may worsen atlantoaxial subluxation risk. More importantly, N2O is a concern in Down syndrome patients who may have undetected cardiac anomalies. The primary concern flagged for Down syndrome is cervical spine instability, making head/neck position during N2O sedation potentially hazardous.
- A. CORRECT. Nitrous oxide is contraindicated in Down syndrome patients primarily because of atlanto-axial instability — the head/neck positioning required during N2O and the muscle relaxation it causes may risk spinal cord injury. Additionally, undetected congenital heart disease is common.
- B. INCORRECT. Mouth props (bite blocks) are helpful for Down syndrome patients who may have difficulty maintaining mouth opening — they are appropriate to use.
- C. INCORRECT. Protective stabilization (passive restraint) may be appropriate for uncooperative Down syndrome patients with proper consent from guardian.
- D. INCORRECT. Rubber dam isolation is appropriate and actually recommended for Down syndrome patients — it improves moisture control and patient safety.
Note: ⚠️ FLAG: The primary dental contraindication in Down syndrome related to sedation is nitrous oxide due to atlanto-axial instability. Rubber dam, mouth props, and protective stabilization can all be used with appropriate consent.
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