While in most cases your baby will let you know when he or she is teeth, there are other changes that can go on in their mouth that is harder to detect.  Having good oral hygiene requires looking inside your baby’s mouth for any unusual changes. One common infection in infants mouths would be oral thrush. This is an overgrowth of yeast which can affect anyone, but more commonly appears in babies younger than six months. While oral thrush often disappears on its own, gum disease may progress. Taking your infant to see a dentist another very important part of promoting good oral healthcare. It is suggested that a baby see a dentist when they cut their first tooth but no latter then their first birthday.