Baby teeth not coming in at 15 months

My son will be 15 months old and has not cut a single tooth.  I called my pediatrician but they don't seem very concerned.  I'm wondering if there could be a medical problem causing this and should I be concerned?

[scottma]

Seeing a pediatric dentist is advised.

[amy0223]

I just worried that this could be a serious problem.  Are there any specific reasons why an infants teeth would not be coming in.  He will be seeing his pediatrician on June 2nd and she will discuss then seeing a dentist but I'm not sure if I should wait that long?

[scottma]

Delayed eruption of teeth may be associated with systemic conditions ,such as rickets, cretinism,cleidocranial dysplasia, or local factors , such as gingival fibrosis ,or idiopathic, which means unknown etiology. If your baby's growth and development is normal, probably there is no serious systemic condition involved.

[nanamom20]

At my daughter's 12 month check-up the pediatrician said if my baby didn't have teeth before 18 months there could be brain damage.  She is now 14 months and have only her two lower teeth and no sign of any others.  Should I be concerned?  Is there any truth to what she said?