My nine month old has the same problem and he has no teeth. He is also still breastfeeding. So I have been just very slowly thickening up his food over time and that seems to be working. I spoke with the dr. and this is what she suggested. I also have given him smashed up avacado in a dip bowl (it is very messy...) and he loves to hold it and lick it and try to eat it. He doesn't seem to choke if he does it himself. He actually does really well with pretzel sticks and crackers too. For some reason if he is putting it in himself he doesn't seem to gag. Those baby puffs he ALWAYS gags on. He can also handle tiny pieces of wheat bread if I put them on the side of his mouth.
I was surprised at this with my son, because my now 6 yr old daughter (S. too) at the same age was eating spaghetti noodles and waffles!
The dr told me for the most part there is nothing to worry about, if it continues for a long time they may need some type of therapy (basically thickening the food, I guess) and working specifically on swallowing. Which you can do on your own. You can talk to your dr. about it at the 9 mo. appt.
Just remember to watch her close with the pretzel and crackers : )
Good luck to you! I used to be a teacher too, till I had my daughter!
S.