With that theory virtually anything could get infected, besides, I have no incisions inside my mouth, the HA was put through the insides of my nose. HA has a very low infection rate in comparison to implants.
Then consider my statement was not specific to YOUR surgery given I made clear the issue of infection was via cuts to the MOUTH and you didn't have that in your specific case. However, in GENERAL, for LARGER cheek augmentations, eg implants, they are put in through the mouth.
Indeed periodontal pathogens from the teeth can find their way into the blood stream when cuts to the mouth are made. Indeed also periodontal pathogens when released via cuts to the mouth can infect other body implants or prosthesis or other areas.