Under general anesthesia for sinus surgery is breathing tube used to keep airway open or is the equipment and medical team literally breathing for you?

During general: Anesthesia for sinus surgery, a breathing tube is placed and the patient is ventilated through it. It is possible to allow the patient to breathe spontaneously as well, with the tube being the conduit for the inspiration and expiration.

One of method: Yes under general anesthesia , some times will be breathing on own, or assisted or or totally paralyzed breathing with ventilator, all depends on the need, & type of procedure all methods are safe, being monitored every second by highly trained and skilled anesthesiologist

Both: The endotracheal tube is placed into your airway to maintain an open, or patent airway. Once the tube is in place you have to be deep under anesthesia to tolerate this tube, at which point you usually are so comfortable that you don't want to breathe. At this point your medical team will breathe for you.

Yes: Usually there is a breathing tube.