1. A method of predicting potential difficult intubation of a subject, comprising the steps of: a) acquiring, using a facial structure analysis system, facial structure data of the subject; b) extracting, using facial structure analysis software of the facial structure analysis system, at least one facial structure variable value from the facial structure data; c) obtaining a predicted potential-difficult-intubation value using an airway classification model and the at least one facial structure variable value; and d) generating a report based on the predicted potential difficult intubation value.