If the teeth are decaed and there are abcess formation then it can cause fever and malaise as ti is the source of infection. Yes,it is called as baby bottle syndrome and it is due to sleeping with bottle in the mouth at night with sweetened drink. You should go to the paedodontist who are the specialist for the children's teeth and get it treated. For more info on baby bottle syndrome you can visit the following link.....http://www.identalhub.com/dental-what-are-nursing-bottle-caries-in-children-802.aspx.
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