Patients
craniofacial anomalies
CERVICAL SPINE DISEASE
American Society of Anesthesiologists (ASA) physical status class I or II patients who were > 18 years of age and scheduled for elective surgery under general anesthesia requiring orotracheal intubation were enrolled in this study. Patients with ASA class ≥ III, dentures, craniofacial anomalies, history of cervical spine diseases, who were at risk for pulmonary aspiration, and who required awake intubation were excluded. Enrolled patients were randomly allocated to a group that underwent the jaw-thrust maneuver (J group) or the McIvor blade (M group) in a 1:1 ratio. Randomization was performed by an independent anesthesiologist using a computer-generated random number table (Random Allocation Software version 1.0; Isfahan University of Medical Sciences, Isfahan, Iran), 5 min before admission to the operating room. Group information concealed within an opaque envelope was opened just before FOI attempt.