The same patient is reclined in the dental chair. What significant finding is expected in the oral cavity?

Correct answer: B. The tongue falls posteriorly and reduces the oropharyngeal airway

• A. The tongue falls backward, not forward. Anterior protrusion is what mandibular advancement devices are designed to produce as treatment.
• B. CORRECT. Supine positioning allows GRAVITY to displace the tongue and soft palate POSTERIORLY against the pharyngeal wall, narrowing the oropharyngeal airway. This is exactly the mechanism of obstructive sleep apnoea, and it is why symptoms are worst in the supine sleeping position and why positional therapy helps some patients.
• C. The soft palate falls posteriorly with the tongue and contributes to the obstruction. It does not elevate.
• D. Gravity retrudes the mandible in the supine position; it does not advance it.

Note: This is also why the semi-supine or upright chair position matters for these patients during treatment, and why sedation carries additional risk for them — sedatives relax the pharyngeal dilator muscles and compound the positional obstruction. Screen with the STOP-BANG questionnaire and assess the Mallampati class before sedating anyone with suspected apnoea.