I have a 13 1/4 year old with 4 teeth (canines) who eats kibble with water. The only thing she can't handle is big treats.
The dog currently not eating (a recurring problem here at GITroublesRUs) has most of his teeth but has lost his appetite. He still likes treats. We know it's a medical issue; we just haven't figured out what it is yet.
Since she's been eating until now, I'd be looking for other reasons for her loss of appetite: kidney, gut, mouth, age...Unfortunately, the list is endless. In the meantime, if she doesn't have food issues, you might try different tasty (soft) goodies like canned food or home-cooked mush or whatever.