Some good news for now. Christine is very pleased with Allie's progress over the weekend, so no surgery for today, not yet anyway. I know, I'm in shock too, after that photo I posted.
Apparently the smell has gone away (meaning tooth maybe isn't dying yet) and there is very little food being flushed when they flush her out. When I mentioned how she was on Saturday, Christine wasn't surprised and it didn't change her assessment. She said the hole between mouth and sinus now seems to be closing rapidly and they aren't going to flush her for a few days to see how she goes. Basically, Allie isn't suffering right now, things seem to be improving so we are leaving her some time for nature to take it's course to see if the hole will close by itself. She doesn't want to go to surgery only to think "gosh this looks like it would heal in a short period of time by itself". May as well see if things continue improving.
And that, my beautiful supportive readers, is a mini victory for today that I am relishing in. I know things may go pear shaped again in the future but this is the best news we have had in weeks. My pony may not need a second surgery after all. Keep everything crossed for her (like I know you already have been).