Several methods have been demonstrated to improve intubating conditions during sevoflurane induction in children. These include opioids, propofol, and addition of neuromuscular blocking agents in pediatric patients. But the study about the comparison of these agents has been uncommon. Frenectomy is common procedure to treat ankyloglossia. It is a short procedure performed under general anesthesia. The investigators aimed to compare intubating conditions among children with propofol, alfentanil or rocuronium after sevoflurane induction.

Inclusion Criteria:

• Children, 1-9 years old scheduled elective frenectomy under general anesthesia

Exclusion Criteria:

• Patients with an abnormal airway, reactive airway disease, gastroesophageal reflux disease, chronic respiratory disease, or a history of an upper respiratory tract infection in the preceding 6-week period