Patient demographics (age, height and weight) will be collected for 546 consecutive patients presenting for dental restoration under general anesthesia. The baseline saturation will be recorded. The induction of anesthesia will be standardized for all patients. All patients will undergo an inhalational induction administered by face mask. After inserting an intravenous (IV) line, rocuronium will be administered. Intravenous propofol and fentanyl could be added at the discretion of the anesthesiologist. The patients will be mask ventilated then be with a mixture of Air/Oxygen (O2) to achieve an FiO2 of 0.3 for 3 minutes after the administration of rocuronium.