M.H.
If you daughter is still on the bottle and using it frequently, it could be something like baby bottle rot on the teeth. Or it could be iron from the formula. It could very well be a cavitiy too. My husband is a pediatric dentist in Plantaion,so I know a little bit about this, but I would have a consultation with a pediatric dentist. If you are interested in seeing someone, my husbands name is Jason Hirsch, Pediatric Dentistry ###-###-####. Office has been there for 30 plus yrs. and is kid friendly. Good Luck-