Which landmark is used to determine the proper size of an oropharyngeal airway?

• A. Corner of the mouth to the earlobe
• B. Corner of the mouth to the nose
• C. Nose to earlobe
• D. Ear to jawline

Answer: (A)

Sizing an oropharyngeal airway relies on a quick, reliable facial landmark that places the device at the right depth in the throat. Measuring from the corner of the mouth to the earlobe gives an estimate of how far back the airway needs to sit so the distal tip sits in the oropharynx, just behind the base of the tongue. When positioned correctly, the tongue is lifted away from the airway opening, helping to prevent obstruction and maintain a clear airway in an unconscious patient.

If the airway is too short, the tongue can still block the passage; if it’s too long, the tip may irritate or stimulate structures in the back of the throat or even push the airway beyond its intended depth. This landmark is favored because it’s quick and generally accurate across adults, making it a practical choice in fast-paced prehospital care. The other measurements serve different devices or contexts—for example, a measurement from the nose to the ear is typically used for nasal airways, not an oral one.