Predictive Values of LEMON and LEON Scores in Elective Oral and Maxillofacial Surgery- Correlation with Intubation Difficulty Scale

Introduction: Airway management can be a major concern, due to the possibility of encountering difficult ventilation and intubation. The Modified Intubation Difficulty Scale (MIDS) is a quantitative scale that can objectively compare nasotracheal intubation. LEMON method which consists of following assessments; Look-Evaluate-Mallampati-Obstruction-Neck mobility and modified LEMON scores (LEON) are popular scoring systems described for airway management due to their easy usability. We aimed to evaluate usability of the LEMON and LEON scores in patients who underwent oral and maxillofacial surgery by studying correlation between each score and the MIDS. Materials and Methods: The records of 72 patients were reviewed retrospectively. At the pre-anesthetic evaluation; airway assessments were recorded according to LEMON, LEON scores; MIDS were recorded after intubation. Patients were allocated into two groups: Non-difficult (NonD; MIDS ≤5) and Difficult (D; MIDS >5). Correlations between scores were analyzed using Spearman’s rank correlation. Receiver operating characteristic (ROC) curve plots were used to determine possible cut-off values; specificity, sensitivity, negative-predictive values for LEON and LEMON scores. In all analyses, p<0.05 were considered statistically significant. Results: LEMON and LEON scores were correlated with the MIDS. Analysis of ROC curve plots revealed 2 cut-off values (≥4 and ≥5) for LEMON; 1 cut-off value (≥4) for LEON score. Among the scores, LEMON (≥4), LEON had the highest sensitivity and negative-predictive values (both 100%); LEON showed higher specificity than the LEMON (≥4) (96.7% vs 91.8%). LEMON (≥5) had the highest specificity (98.4%) but the lowest sensitivity (90.4%), negative-predictive value (90.9%) among the group. Conclusion: LEON scores ≥4 can be effectively used with 100% sensitivity, 96.7% specificity and, 100% negative-predictive-value for predicting difficult airway and intubation in elective maxillofacial surgeries.