Related Experiment Video
Updated: Jun 13, 2026

Point-of-Care Ultrasound: A Review of Ultrasound Parameters for Predicting Difficult Airways
Published on: April 7, 2023
Evaluation of the upper lip bite test in predicting difficult laryngoscopy
Neelima Myneni1, Anthony M O'Leary, Michael Sandison
1Albany Medical College, Albany, NY 12208, USA.
Study Objective:
To evaluate the accuracy of the upper lip bite test (ULBT) in predicting difficult laryngoscopy.
Design:
Prospective, observational outcome study.
Setting:
Operating room of a large tertiary-care academic medical center.
Patients:
6,882 consecutive adult, ASA physical status I, II, III, IV, and V patients, scheduled for procedures in all surgical specialties.
Interventions:
Upper lip bite test class was determined for all patients preoperatively.
Measurements:
The Cormack & Lehane grade of laryngeal view was determined at endotracheal intubation.
Main Results:
Only 171 patients had ULBT class III, predicting a difficult laryngoscopy, while 173 patients presented with a Cormack & Lehane grade of 3 or 4. Of the 173, 14 patients had a previous ULBT class of III. Sensitivity and positive predictive value of the ULBT were 8.1% and 8.2%, respectively.
Conclusions:
The ULBT is a poor predictor of difficult laryngoscopy when used as the single bedside screening test in a North American patient population. Its use cannot be recommended.
Related Concept Videos
Assessment of the Mouth
Mouth Inspection
The inspection begins with visually examining the mouth for symmetry, color, and size.
Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques
Assessment of Airway, Skin Color, and Use of Accessory Muscles
Introduction
The initial evaluation of a patient's respiratory system...
Cardiopulmonary Resuscitation II: ACLS Airway Management

