Some baby's do not have a tooth break through until around their first birthday but generally by the age of 2 years nearly half of all 20 teeth will appear for most babies. Signs of teething vary much as the age at which they appear. Symptoms can creep in at about 3 - 4 months of age. Excessive drooling is a sure sign that your baby has entered the teething stage. This drooling can cause dry chapped skin around the mouth and the chin adding external discomfort as well.
Some babies become very fussy and irritable while others have no problem at all.
You may not even know your baby has cut a tooth until they use it to nibble on you. Don't be alarmed if they don't eat as much as they generally do, during this period. They may not want a bottle or to nurse as often either, due to the pain. Remember their little gums are probably very sore, and red and swollen as well. You may even see them tugging at their ears.