I am not one of the "experts" but I don't think there is much to be done for it other than clean it and perhaps apply some ointment. It has not punctured completely through the shell. I am assuming that the damaged area will be a permanent scar and those scutes may even peel off. Others can give you a better idea if what to expect. May I ask how this happened? It appears to be teeth marks, perhaps a cat or dog? Is there any damage to the underside?