This study evaluates the endotracheal tube cuff pressure of a taper-guard cuffed tube during tympanoplasty with ipsilateral rotation of head, compared to the contralateral rotation of head.

The investigators will performed the ipsilateral rotation of head against the fixed tube in half of participants or the contralateral rotation of head in the other half.

The inflation of the endotracheal tube cuff is very useful to prevent aspiration of contaminated substances into lung past endotracheal tube and leakage of gas during positive pressure ventilation. However, excessive inflation of endotracheal tube cuff frequently causes tracheal mucosal damage, which can increase the incidence of sore throat, hoarseness, and coughing after surgery.

Taper-guard cuffed tube was newly developed. Taper-guard endotracheal tube is more effective in providing a sealing effect than a cylindrical endotracheal tube in an in vitro study. However, recently, it was reported that the cuff pressure of a Taper-guard endotracheal tube significantly increased after a positional change from the supine to the lateral flank position, compared to that of a cylindrical endotracheal tube. However, during tympanoplasty, the investigators need to rotate head for proper position.

In this study, therefore, the investigators investigate the difference of the endotracheal tube cuff pressure of a taper-guard cuffed tube between ipsilateral and contralateral rotation of head against the fixed tube during tympanoplasty.

Inclusion Criteria:

• American Society of Anesthesiologists physical status classification I-III for a tympanoplasty under general anesthesia

Exclusion Criteria:

• history of difficult intubation, limited neck movement, respiratory diseases, and body mass index >35kg/m2