Sorry to hear about the trauma to your son. There are some options available for ear restoration but it largely depends on patient preference and surgical expertise.
The two main options are autologous reconstruction, and prosthetics.
Autologous reconstruction is usually at least 3 surgeries and requires cartilage to be harvested from the ribcage. This is then meticulously carved and put under the skin of where the ear used to be. Additional surgical stages are then done to refine the reconstruction. Probably the best known surgeon that does this technique is Dr. Burt Brent. I believe that he is located in Orange County close to you. Rarely does the autologous reconstruction look perfect, but the advantage is that it is living tissue that does not need maintenance.
Another option is a prosthesis. This almost always looks better than an autologous reconstruction since an anaplastologist / prosthetic specialist can fashion an ear that matches the other side. It can then be fixed with adhesive or with titanium implants and magnets. The titanium implants are surgically placed but it is a less involved procedure than the rib harvest reconstruction.
Good luck to you, but know that there are some nice options out there.
Michael Kim, MD