A few are born with a tooth already through. Others have no teeth at one year old. Most get their first tooth at around six months, usually in front and at the bottom. Most have all their primary teeth by about two and a half. The first permanent 'second' teeth come through at the back at around the age of six.
Some teeth come through with no pain or trouble at all.
At other times you may notice that the gum is sore and red where the tooth is coming, or that one cheek is flushed. Your baby may dribble, gnaw and chew a lot, or just be fretful, but it's often hard to tell whether this is really due to teething. Avoid rusks because almost all contain some sugar. Constant chewing and sucking on sugary things can cause tooth decay, even if your baby has only one or two teeth. For babies over four months old you can try sugar-free teething gel rubbed on the gum.