Thanks for using Health Care Magic. Read your query. Orthodontic treatment requires tooth extraction based on many factors including the position of the erupting and erupted tooth,amount of space required ,type of irregularities present in the mouth and many others ,which the orthodontists keep in consideration and then plan a treatment. I would suggests if you are so worried about removal of another four teeth,go ahead with a second opinion and then proceed with the treatment. Follow the post treatment maintenance with the retainers and the dentist advice for better prognosis. Hope this was helpful. Thanks and regards.