Ethnic considerations in the upper lip bite test: The reliability and validity of the upper lip bite test in predicting difficult laryngoscopy in Koreans

Several methods have been used to predict difficult tracheal intubation. Among recently suggested methods, the upper lip bite test (ULBT) could serve as a good predictor. Soft tissue and skeletal hard tissue profiles are affected by many factors including ethnicity. We aimed to assess the clinical utility of the ULBT in Koreans while considering ethnic differences.