A correct preoxygenation can be obtained after a 3min delay of calm ventilation through a tight mask thereafter mask is used to make the patient breathing before intubation. Most tight masks are actually sold but they have never been compared in studies. The aim of this study is to compare air leaks with standard facial mask and QuadraLite masks during preoxygenation and induction of anesthesia.

Inclusion Criteria:

• edentulous patients
• age > 55 years

Exclusion Criteria:

• pregnancy or breast-feeding, patients on tutelage or guardianship
• patient unable to understand the protocol
• anesthesia in emergency or with full stomach