<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi! I have a1 yr old daughter and and since past 1 month I see that her mouth smells very bad , be it anytime of the day. She is eating all kind sof food now and has not started brushing yet . What can I do to prevent her mouth from smelling bad?  <response>: Hi. Welcome to Chat Doctor. As per your complaint bad smell from the mouth of a 1-year-old infant is most commonly due to poor oral hygiene leading to bacterial overgrowth and causing bad smell. It can also be due to any decaying toothteeth or gum infection. Persisting cold and sinus infections can be a cause. As you have not started brushing her teeth, poor oral hygiene is appearing to be the culprit. I would suggest you to consult a Periodontist and get evaluated and a thorough clinical evaluation done. In case if there is any infection then it has to be treated accordingly. In case if there is nothing ruled out then maintaining a good oral hygiene by cleaning teeth after feeding, giving plenty of water can help. Start brushing her teeth daily... Hope this helps. 