I'm a new yorkie mom of a cupcake. Tatiana is three years old, and she weighs 3 lbs. I have no idea how much she weighed at three months, as she was raised by her breeder.
I've only had Tatiana for a few days. Off the top of my head, I find taking care of Tatiana's teeth a little challenging. Because she's so small, she has a small mouth, and small teeth. I'm using a dental spray to spray her mouth. When I spray the front of her teeth (where she can get build-up), the spray goes up her nose (because she's so tiny, her precious nose sits right above her teeth). The poor dear sneezed. She's okay -- she has no harm. I had to spray my finger, and brush the liquid against her teeth.
I will be purchasing the dental gel to gently brush on her front teeth. I will reserve the spray to spray DOWN her mouth for the back teeth.
Again, I've only had Tatiana for a few days. This is the first situation I experienced where her size created a limitation -- no dental spray for the front teeth. Of course, I think I easily (and happily) worked around that.
Hope this helps.