the goal of the observational study to measure the effectiveness of neck ultrasound in prediction of difficult intubation in adult patients

All participant undergoing elective surgery under general anesthesia will go a detailed preoperative sonographic assessment by the anesthesiologist who has experience in airway ultrasound for measurement of Hyomental distance, thyrohyoid distance, thyroid cricoid, anterior soft tissue thickness at levels of hyoid bone, cricoid cartilage and vocal cord and all measurement will be measured in neutral and sniffing position.

after induction of general anesthesia intubation will done by macintosh laryngoscope and degree of difficulty of intubation will be measured by cormack-lehane classification without any external manipulation

Inclusion Criteria:

• Adult patients above18 years old
• Both sex
• Requiring general anesthesia with endotracheal intubation

Exclusion Criteria:

• Emergency surgery,
• patients with limited mouth, head or neck movement,
• patients with temporomandibular joint impairment,
• fracture or tumors of mandible,
• patients requiring awake intubation,
• uncooperative patients,
• any cervical spine limitation movement
• neck swelling or tumor
• Prominent teeth deformities.

all population undergoining surgical operation requiring general anesthesia and endotracheal intubation

for 1 year