Why would the doctor remove so much of my septum when it was only supposed to be straightened?

Without actually examining inside your nose it is difficult to fully answer your question regarding the changes you are noting. The septum is one piece of cartilage in the front part of your nose and bone in the back and along the floor of your nose. If it is deviated to one side, making it straight will necessarily push it over to the more open side, like moving a wall inside a room to the middle of the room so that both sides are equal. To move the septum to the middle, sometimes deviated portions of cartilage need to be removed.  All the best,

Dr. Brace

Without more details it is difficult to say but if the septum is really curved, sometimes removing a portion and using pieces that were removed to bolster the cartilage can be helpful.

The septum is normally a midline structure.  When it is deviated to one or both sides, septoplasty surgery may be indicated.  The surgery may require removal of cartilage and bone vs repositioning the cartilage. It is not clear to me by your comment what your underlying concerns are.  I would recommend you seek an additional opinion if you have concerns with your breathing or results.  Good luck