A: April, I do not think you have to worry. The eruption of teeth is a very individual event. Each person erupts their teeth at their own rate. This is why averages are used—since there is such a wide variety. If your niece had all her teeth at 22 months of age, she is actually earlier than average. Your son is probably on a later schedule and will probably be fine. If he does not have 20 teeth by the age of 2½ years, you should have him seen by a dentist. Some children are actually missing teeth and others do have problems with eruption.