Difficulties airway significantly contribute to the morbidity and mortality associated with anesthesia. Identifying situations and patients at risk for airway management problems is the key to optimal care and has been the focus of numerous publications. Although controversial, Body Mass Index (BMI) is considered as associated with difficult intubation in both and operating theaters. A modified measurement of SMD is obtained with the head in neutral position (SMD neutral), then the difference between SMD extension and SMD neutral was calculated and it was referred to as sternomental displacement (SMDD). SMDD was proved to be a good objective predictor for difficult laryngoscopy in adult patients, and its predictive ability was increased when combined with other tests as neck circumference (NC). To the best of our knowledge, the validity of the SMDD test was not previously assessed in obese patients.

Inclusion Criteria:

• Patients of either sex, aged between 18-60 years old, ASA physical status II & III with BMI > 30 Kg/m2 undergoing elective surgical procedures under general anesthesia using endotracheal intubation by conventional laryngoscopy.

Exclusion Criteria:

• neuromuscular disorders, craniofacial abnormalities, abnormal dentition, lesions or scares in head and neck limiting the neck mobility, uncooperative, who needed awake intubation and patients who underwent emergency operations

Patients of either sex, aged between 18-60 years old, ASA physical status II & III with BMI > 30 Kg/m2