Ketamine could lead to these sorts of secondary effects. By taking this medication, the patient would be made more comfortable, especially in the surgical setting, but it could also lead to secretions that might make it more difficult for the patient to have a clear breathing pathway during the procedure.
Due to the average rate of growing starting to properly sprout at the age 11, surely those years around it would be the greatest difference. I think there is about a 15cm difference on average.