To be honest and answer your question, all of the Iams formulas are poor quality. :/ Of course, it is a step above Ol Roy and such, and I know you're a teenager. I definitely recommend begging your Mom to switch them over to at least Nutro (and other similar brands that are available at pet stores - avoid grocery store brands!), though, they have good formulas that are much more nutritional and higher quality for your pups. I know you love them, and of course you are doing the best you can for them, but the cost of Iams is very comparable to Nutro Natural Choice... just a few dollars more, especially since both of your dogs are small breeds.

Also, no size kibble will help dental problems. Kibble sticks to the back of their teeth after they're done eating, which will cause more dental issues if anything. I recommend brushing their teeth daily and offering them good dental chews (such as Greenies & similar products) and looking into raw meaty bones.