The primary reason that we surgeons wear masks is traditionally it was thought to reduce infection as small droplets leave mouth when you are breathing and talking. Nasal as well. in other words, transmission TO patient from surgeon. Some studies showed no effect.

tpcook: Surgical masks are not N-95 or KN-95.

N-95/KN-95 masks are to filter out what is breathed in... They should be checked for fitness. These protect the person wearing the mask (and also the person in front of the person wearing the mask), even better than surgical masks.

Also, surgeons wear masks so they can stick their tongue out at the anesthesiologist;-)