I found they stay in place if you use a tube holder. Our company uses the EndoGrip.
(Excuse the cut and paste)
The EndoGrip™ features a simple two-piece construction that promotes quick applications, strength and easy repositioning of the tube from side to side. Patented* and FDA cleared clamp is engineered to secure all standard adult-sized ET tubes, including cases of severe facial burns, lacerations, copious bleeding, vomiting or bearded patients. Flexible and cushioned Velcro® strap fastens to itself and not patient's face or head. Acts as an effective bite block, allowing a large portion of the patient's mouth to remain accessible for suctioning.