Condyle-tragus distance: a simple anatomical marker to predict difficult airway management

Position du problème et objectif(s) de l’étude

Preoperative airway assessment is a critical step in reducing the risk of complications during general anesthesia. However, commonly used predictive tools—such as the Mallampati score, thyromental distance, or mouth opening—often lack sufficient sensitivity and specificity. Recent interest has turned to anatomical parameters that reflect mandibular mobility. The condyle-tragus distance (C-TMD), which indirectly reflects temporomandibular joint translation, may offer a simple and objective way to anticipate difficult airway scenarios. Our objecective is to evaluate whether the condyle-tragus distance is an independent predictive factor for difficult tracheal intubation and/or mask ventilation, and to compare its diagnostic performance with standard preoperative predictors.

Matériel et méthodes

A prospective observational study was conducted in the operating room on 50 adult patients (ASA I–III) scheduled for elective surgery under general anesthesia. C-TMD was measured in the sitting position with the mouth fully open. Classical predictors (Mallampati score, thyromental distance, mouth opening) were also assessed. Intraoperative data included the ease of mask ventilation, Cormack-Lehane grade, number of intubation attempts, and need for alternative airway devices. Statistical analyses included group comparisons, correlation tests, and diagnostic accuracy measures (ROC curves).

Résultats & Discussion

Out of 50 patients, 08 patients (16%) experienced difficult intubation. Mean intubation time was longer in patients with a C-TMD < 13 mm (49.5 ± 6.2 s) than in those with a C-TMD ≥ 13 mm (44.1 ± 5.4 s, p < 0.05). First-attempt success rate was 100% in the C-TMD ≥ 13 mm group, compared to 75% in the C-TMD < 13 mm group. A moderate negative correlation was found between C-TMD and Cormack-Lehane grade (r = –0.41, p < 0.01). The area under the ROC curve for C-TMD as a predictor of difficult intubation was 0.76 (p < 0.05). A threshold of C-TMD < 13 mm showed the best agreement with difficult laryngoscopy (κ = 0.52, 95% CI: 0.29–0.72), with an odds ratio of 8.5 (95% CI: 2.1–34.3). Sensitivity was 66.7% (95% CI: 35.4–88.7), specificity 90% (95% CI: 71.4–97.4), with a positive predictive value of 80% and a negative predictive value of 81.8%.

Conclusion

The condyle-tragus distance is a straightforward and reproducible anatomical measurement that shows promise in predicting difficult airway management. Its incorporation into routine preoperative assessment could improve patient safety and guide anesthetic planning. Further studies with larger sample sizes are needed to confirm these preliminary findings.

Auteurs

Hamza BEN KHEDER, Fatma GARGOURI, Elhem HOUICHI - (1)Chu Sahloul, Sousse, Tunisie

Orateur(s)

Hamza BEN KHEDER (Sousse)