Are cephalometric X-ray's essential in orthodontic treatment??

As an orthodontist, I can tell you that a lateral cephalometric film is necessary to properly diagnose any patient prior to the start of orthodontic treatment.  Are you sure that you saw a certified orthodontist, and not just a general dentist that does orthodontics?  There is a difference. An orthodontist recognizes the value of information gained from having a 'ceph'.   The general dentist, Dr. Cobb who has also responded would agree that a root canal would not be preformed without having the appropriate xray. Nor does an orthodontist provide treatment without having a ceph. As well, you mentioned that a periodontist changed your bite by retracting lower arch.  Periodontists are involved in taking care of gums and bone supporting your teeth, and typically do not do anything to cause such major changes in one's bite as you describe. Hope this helps,

A cephalometric radiograph is not a requirement. I have never done one on my Invisalign cases. Ask to see the end result. Since you have 39 trays (more than any case I have ever done), I would suspect that the teeth are being flared out and then will be retracted back. So, this may be a temporary phase that will be corrected in the end. The ClinCheck will be able to show you how the teeth move.