Teething at 3.5 months is also considered normal for infants. Generally, babies start teething around 6 months of age, but it does not mean that it has to be 6 months, it is considered normal if the tooth erupts in a good position and if the tooth is very strong after eruption. Clinically, for early teething, there is the extreme case called birth tooth, which means that the newborn has a tooth in the mouth, and this tooth is considered normal if it is strong. However, if a birth tooth becomes loose it is generally recommended that the birth tooth be extracted as soon as possible because a loose tooth may cause respiratory risks and pose a greater risk to the baby.