The Average Length from the Incisors to the Vocal Cords is Approximately 15 Cm, and the Distance from the Vocal Cords to the Tracheal Carina is 12 Cm

(From Campos J. Lung isolation in patients with difficult airways. In: Slinger P, ed. Principles and Practice of Anesthesia for Thoracic Surgery. New York, NY: Springer; 2011:247-258, with permission.)

The average distance from the tracheal carina to the take-off of the right upper bronchus is 2.0 cm in men and 1.5 cm in women. The distance from the tracheal carina to the take-off of the left upper and left lower lobe is approximately 5.0 cm in men and 4.5 cm in women. These anatomic distances apply to individuals with a height of 170 cm.