My son is 16 months old . he just had his 6th tooth. is this normal?

Not really: Every child develops teeth differently. There are typical time periods that the teeth usually erupt into place, but there is no hard and fast rule. Some children develop and have teeth erupt in sooner or later then others. If you are still worried, have the baby looked at by your dentist.

Absolutely: Some children get teeth earlier than the average, some later. The order of eruption of teeth and their positions (occlusion) and spacing is more important than the timing. Your child should already be seeing a pediatric dental specialist, who is trained in growth & development, for evaluation. The pedodontist will also give you guidelines to help you care for your child's teeth.