As permanent teeth begin to erupt many parents become concerned when there are two teeth in place.  It is not uncommon to have a permanent tooth erupt behind the baby tooth.  It is more common to be noticed by parents in the lower jaw, but can happen in the upper jaw as well.  Many parents think their child’s’ teeth look like shark teeth.  It happens because of “incisor liability.”  Incisor liability is the term used by pediatric dentists to describe the difference in the size of the new permanent anterior teeth compared to the baby teeth that were in their place.  On average the upper permanent teeth are 7.1 mm larger, and the lower teeth are 5.1 mm larger than the baby teeth.

During a child’s development he or she will also grow the accommodate the teeth; however, the amount of growth that occurs is not always sufficient to allow for proper alignment.  If a child has crowding in his or her baby teeth he or she will likely have crowding in his or her permanent teeth.  Because of this spacing in between baby teeth is beneficial to allow for a child to accommodate the larger permanent teeth.

Typically when a permanent tooth erupts behind a baby tooth it is not a true dental emergency.  If your child is having discomfort or unable to exfoliate the baby tooth on his or her own a pediatric dentist may be able to provide assistance as there may be too much root remaining for the child to comfortably remove the tooth on his or her own.   The pediatric dentist will also evaluate your child’s development and may recommend an appliance to help with spacing, or provide referral to an orthodontist for evaluation.