My 5 months old child has started teething problems. He keeps crying and wants to bite into everything he can lay his hands on. What am I supposed to do. Teething, medically termed as odontiasis, is the process by which an infant’s teeth erupt, or break through, the gums. Teething is also referred to as “cutting” of the teeth. The onset of teething symptoms typically precedes the eruption of a tooth by several days. While a baby’s first tooth can appear between 4 and 10 months of age, the first tooth usually erupts at approximately 6 months of age. Some dentists have noted a family pattern of “early,average,or late teethers.