It is normal for babies to teethe at 4 months. Usually, baby’s milk teeth start to erupt at around 4 to 10 months of age. If teeth do not erupt after 13 months, this is called delayed teething and requires prompt medical attention. Usually, two sets of teeth erupt in a person’s lifetime. The first set of teeth, called baby teeth, will start to erupt between 4 and 10 months of age, and there are about 20 of them. Some babies will start to develop milk teeth at around 4 months of age, while some babies may not develop milk teeth until around 10 months of age. So teething at 4 months is a normal phenomenon and there is no need for concern or special treatment. If the baby does not have milk teeth eruption after more than 13 months, clinically known as delayed teething, need to consult the doctor in time, under the guidance of the doctor to clarify the cause of the disease and then treatment. When your baby is teething, parents need to pay attention to the cleanliness and hygiene of your child’s mouth. Usually after eating milk, you need to give your baby a good clean mouth, such as using a cotton swab moistened with water to clean the residual milk.