Ultrasonographic Parameters in Prediction of Difficult Laryngoscopy in Non-suspected Difficult Airway Patients

Inclusion Criteria: * Aged 18 - 65 years. * Both sexes. * Patients who aren't suspected to have a difficult airway after preoperative airway assessment by conventional clinical tests such as modified Mallampati classification (MMC), thyromental distance (TMD), inter-incisor distance (IID), cervical mobility (CM), And neck circumference (NC). * American society of anesthesia (ASA) I, II, and III physical status. * Scheduled for elective surgery under general anaethesia. Exclusion Criteria: * Patients with maxillofacial injury and airway trauma. * Patients with a history of previous difficult intubation. * Patients with anatomical abnormalities. * Neck scarring, swelling, or burn. * Pregnancy. * Obesity.