Hi there ...it could be because of many reasons ...one major reason being bottle feeding at night... If that is so...then u should make a point of giving her water after bottle feeding so that all the sugary milk will be washed out from the teeth surfaces ... Either she can drink a glass of water or rinse her mouth with it... This can also be due to calcium deficiency, trauma at an early age when her teeth were developing, or medications effects while pregnancy ..and many more ...!! But now all u need to do...is visit a nearby pediatric dentist and get them treated properly...because the condition of these teeth will influence the health of permanent teeth... Take care ...!!

Hi.. You need to consult child specialist Pedodontist for this. Your child might need pulpectomy and cavity fillings. Regards

You must see a pedodontist.