Can you tell me what can be happening if an 11 month old hasn't had his first tooth eruption yet?

Delayed eruption: Everything may be completely normal other than your child is on the extreme of tooth eruption scale. At the age of one year would be to have your child seen by a pedodontist.

Dont worry: Probably just a late teether..If your child has no other health problems i would not be concerned...

Late Teeth: Most likely the answer is that the child is going to get their teeth a bit late. 11-12 months is not terribly late for a child to get their first teeth. If you have further concerns please have the child see a pediatric dentist.

Tooth eruption: The first tooth eruption of children occur within a range from as early as 3 mos to as late as 14 months. The later the eruption the less the risk of dental caries. The children adapt to late tooth eruption quite well. Thus, be patient and your child will have teeth before you know and will have a full set of teeth by 36 months. If however by 16 months there are no teeth visit your dentist.