Using temporomandibular joint mobility to predict difficult tracheal intubation

Area of Science:

• Anesthesiology
• Oral and Maxillofacial Surgery
• Diagnostic Accuracy

Background:

• Predicting difficult intubation is crucial for patient safety during anesthesia.
• Temporomandibular joint (TMJ) mobility has been explored as a potential predictor, but its reliability needs further validation.

Purpose of the Study:

• To assess the reliability and accuracy of temporomandibular joint (TMJ) mobility measurements in predicting difficult tracheal intubation.
• To evaluate specific TMJ mobility parameters, including incisor gap and degrees of protraction, as preoperative screening tools.

Main Methods:

• A prospective, observational, single-blind study involving 762 patients undergoing elective surgery requiring tracheal intubation.
• Measurements included maximum mouth opening, jaw excursion, degrees of protraction (using a digital inclinometer), and incisor gap (using a vernier caliper).
• Laryngeal view was assessed using the Cormack-Lehane classification post-anesthesia induction.

Main Results:

• Patients in the easy intubation group exhibited significantly higher degrees of protraction and incisor gap compared to the difficult intubation group.
• The incisor gap demonstrated higher sensitivity (88.37%) and specificity (95.71%) than degrees of protraction (58.14% and 59.76%, respectively).

Conclusions:

• Incisor gap measurement is a highly sensitive and specific indicator for predicting difficult tracheal intubation.
• Degrees of protraction also show potential utility, though less accurate than incisor gap.
• These TMJ mobility measurements may serve as valuable routine preoperative screening tests to identify patients at risk for difficult intubation.