Background: Nasotracheal intubation can lead to severe complications like epistaxis with excessive bleeding. The advancement difficulty of the tube faced during nasal intubation is one of the fundamental causes of this condition. The present study aimed to evaluate the effectiveness of Computed tomography-guided nasotracheal intubation in predicting tube advancement difficulty and preventing epistaxis.

Material and Methods: 60 maxillofacial surgery patients were included in the study. The space where the tube will be passed in the internal nasal valve region was measured horizontally (distance between inferior concha and septum) and vertically (distance between inferior concha and hard palate) by Computed Tomography. The patients were divided into two groups, 'easy' (n=28) or 'difficult' (n=32), according to the effort required to advance the tube through the nasal passage.

ROC analysis was performed, and cut-off values were determined to reveal the distance values at which difficulty may be experienced while advancing the tube. The cut-off values were 1.09 cm and 0.39 cm for the vertically and horizontally distances, respectively.

Inclusion Criteria:

• Aged 18 to 65 who underwent bimaxillary orthognathic surgery
• defined as ASA (American Society of Anesthesiology) I or II

Exclusion Criteria:

• The lack of preoperative CT scans
• airways evaluated and considered difficult by the anesthesiologist
• airways assessed and considered not appropriate for right angle endotracheal (RAE) tube with7.0 mm internal diameter
• history of sinusitis or head trauma
• anticoagulant therapy

Sixty health volunteers who went orthognathic surgery