Airway management is one of the most important skills in everyday practice of anesthesia. Improper airway management might lead to high risk of mortality. clinical parameters alone cannot predict all potentially difficult airways. Ultrasonography (US) might play a role as a potential screening tool for difficult airway and given the limited empirical study in this field; this research will focus on using ultrasound to predict difficult airway and difficult mask ventilation for patients undergoing elective operation under general anesthesia. Methodology This study is Prospective observational . The study will be conducted in Cairo University Hospital Participants are adult patients (above >40 years), (BMI < 35) with American Society of Anesthesiologists physical status (ASA-PS) I-III, scheduled for elective surgery under general anesthesia with tracheal intubation . Exclusion criteria included patients with history of difficult intubation or apparent airway abnormalities (facial scars, neck scars, unstable cervical spine and history of cervical spine fixation) that would require alternative technique other than endotracheal intubation with direct laryngoscopy. Also, edentulous patients, patients undergoing emergency procedure and pregnant women are excluded from the study. Hypothesis The investigators hypothesize that combined class 3 ULBT and DSE >2 cm can accurately predict difficult laryngoscopy in adult patients undergoing elective procedure under general anesthesia with endotracheal intubation.

Inclusion Criteria:

• Participants will be adult patients (above >40 years) ( BMI < 35) with ASA-PS I-III, scheduled for elective surgery under general anesthesia with tracheal intubation.

Exclusion Criteria:

• Patients with history of difficult intubation or apparent airway abnormalities (facial scars, neck scars, unstable cervical spine and history of cervical spine fixation) that would require alternative technique other than endotracheal intubation.

Edentulous patients patients undergoing emergency procedure pregnant women were excluded from the study.

adult patients (above >40 years) ,( BMI < 35) with ASA-PS I-III, scheduled for elective surgery under general anesthesia with tracheal intubation