13 Year Old Missing Lateral Incisors - Close Space or Open for Implants?

Without question, the wisest choice aesthetically  would be to orthodontically open the spaces to make sufficient room for dental implants.   I have seen too many cases where canines are moved into the positions of the congenitally missing lateral incisors  and this is an aesthetic disaster most of the time!  For an orthodontist this can be difficult to do and time consuming, but it is the best option.  Find an orthodontist that enjoys the challenge of this case and have them create the spaces.  When the braces are ready to come off retainers will be made to hold the spaces intact until your son is old enough for the implants.  Around age 18 he can have a 3D CT scan taken of the areas that are to receive the implants.  If the bone is sufficient at that time procede with the implants.  If not, he may have to wait a couple more years. Good luck.

If you are looking at long term solutions, either option will work.  If you are looking for long term aesthetic solutions, I would go with the implants.  This will give your son 1.) more teeth to function with, 2.) a more natural smile, and 3.) more confidence in that his teeth and mouth will appear normal when compared to his peers.  Trying to make canines look like laterals is very difficult.

I would recommend placing implants as an ideal esthetic outcome.  The cases that close the space and reshape the canines to look like lateral incisors do not look as good in my opinion.  Often the facial profile will look flat and the bite will not function as well.  Maintaining the bone width and proper spacing  for future implants can be a challenge though. He may be a candidate to place the implants as early as 18 years old depending on how quickly he matures.  

It is true that teeth do move as they have a natural ligament surrounding them while a dental implant fuses to bone and will not move. Dental implants are stronger than your natural teeth. 

A good orthodontist should be able to have a stable bite and promote longterm stabilization to keep teeth from moving.  Having orthodontics is a lifelong commitment to wearing retainers if you want the teeth to not move at all.  Good luck!