Difficulty in managing the airway is the single most important cause of major anesthesia-related morbidity and mortality. The currently used clinical method of predicting airway difficulty used by anesthetists is limited and not very highly sensitive or specific. Any additional bedside method that increases its specificity and sensitivity would be valuable. This project is designed to study and measure the tongue thickness and oral cavity height by using an ultrasound scan and comparing them with the same measurements obtained by CT scan. These will also be compared to a more complicated measurements used in previous studies to investigate any correlation with the currently used clinical methods. This information will help us decide if ultrasound may help Anesthesiologists assess difficulties in airway management in a more accurate, precise and reliable simpler method.

Inclusion Criteria:

• Age between 18 to 80 Years
• Gender: Both males and females are eligible for the study
• ASA I-III
• Scheduled for CT-scan of the head and neck as part of medical investigation (for test validation part)

Exclusion Criteria:

• Volunteer/ patient refusal
• Language Barrier
• Known oropharyngeal, laryngeal or head and neck disease or cancers
• Multiple amalgam fillings of the teeth
• Past history of oral or head and neck surgical procedures
• Past history of burns or radiotherapy of the head and neck region
• Presence of any scars, sinuses, infection, swelling, cysts in the head and neck region

Patients scheduled for high resolution computerized tomography (CT scan) of the head and neck as part of their medical investigation of thyroid or laryngeal disorders will be recruited for this study.