To select the proper size oropharyngeal airway, you should measure from the:

• A. Corner of the mouth to the superior ear.
• B. Center of the mouth to the posterior ear.
• C. Angle of the jaw to the center of the mouth.
• D. Corner of the mouth to the earlobe.

Answer: (D)

The main idea is choosing the airway length by estimating how far the tube will reach into the throat so it stays behind the tongue and keeps the airway open without pushing into the larynx. Measuring from the corner of the mouth to the earlobe gives a depth that closely corresponds to the distance into the oropharynx, where the tongue tends to obstruct the airway if not displaced. This helps ensure the tip sits in the proper space behind the tongue rather than too far forward or too far back. If the measurement is too short, the device may not effectively lift the tongue away from the airway; if it’s too long, it can irritate or enter the larynx and cause trauma or gagging.