However, this time is not definite and there are always various special cases, some babies develop early and erupt early, some babies develop late and erupt late and there are very special clinical cases, for example, some babies are born with teeth, called birth teeth. If the birth tooth is very strong and in a normal position, it is considered a normal tooth, but sometimes the birth tooth may become loose and needs to be extracted in order to ensure a clear airway and avoid obstruction. In addition to early growth, there are also cases of late growth. Some teeth may start to come in when they are close to 1 year old, but as long as the growth conditions are good and the texture and position are normal, it is considered normal tooth eruption.