It is estimated that endotracheal intubation is performed on some 8 million patients per year in the United States. Of these endotracheal intubations, approximately 80% are performed by direct laryngoscopy with transoral placement of the endotracheal tube (ET) into the trachea. The incidence of unsuspected difficult intubation is estimated to be higher at approximately 3%. One factor that contributes to difficult intubation is poor visualization of the airway.