Determination of tracheal tube insertion depth for dental procedure and oral and maxillofacial surgery

Incorrect endotracheal placement of the tracheal tube can lead to serious complications, such as laryngeal nerve paralysis and accidental extubation [1]. In oral and maxillofacial surgery and dental procedure, the head of the patient was covered in drape, and an anesthesiologist cannot often see tracheal tube. In addition, surgeon (or dentist) may move the head of the patient. Flexion of the neck results in increase in the insertion depth of tracheal tube [2,3]. Conversely, extension of the neck results in decrease in the insertion depth of tracheal tube [3]. Position of the neck results in the insertion depth of tracheal tube is presented in Figure 1.