1. A non-transitory computer-readable storage medium having facial structure analysis software code stored therein that, when executed by a processor, causes the processor to perform analysis for predicting potential difficult intubation of a subject including the steps of: a) acquiring facial structure data of the subject; b) extracting at least one facial structure variable value from the facial structure data; c) obtaining a predicted potential-difficult-intubation value by inputting the at least one facial structure variable value into an airway classification model; and d) generating a report based on the predicted potential difficult intubation value; wherein step b) includes extracting at least three facial structure variable values from the facial structure data, and step c) includes obtaining the predicted potential difficult intubation value by inputting the at least three facial structure variable values into the airway classification model; and wherein the at least three facial structure variable values include a face-brow-nose-chin ratio, at least one jaw-neck slope high and low value, and at least one nose-tilt down and up value.