Is it possible for me to go from 225cc moderate profile silicone implants to 450cc ultra high silicone implants? (Photos)

Yes, you should be able to further increase breast size significantly.***The much more important question with be: which breast implant (volume and profile) will be the correct choice when it comes to  achieving your desired outcome when it comes to breast size/shape/symmetry…?  Online consultants will not be of much specific help to you in this regard.
Generally speaking, the best online advice I can give to ladies who are considering revisionary breast augmentation surgery (regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals  with your plastic surgeon. This communication will be critical in determining  breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as  “natural” or "D or DD cup” or "a lot bigger" etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on  who makes the bra; therefore, discussing desired cup  size may also be inaccurate.   
3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery ( after the use of temporary intraoperative sizers).  Viewing the patient's chest wall in the upright and supine positions, with temporary sizes in place, help select  the best breast implant size/profile for the specific patient.
 Best wishes. 

Good afternoon!Thanks for the photos- absolutely you can reach that size and you will look awesome!!

Dear T girl,Breast revision surgery is the most difficult plastic surgery procedure performed. Botched breast surgery alters normal tissue planes and laxity, the ability of breasts to heal properly, and leaves scar tissue that dramatically affects the level of difficulty of the corrective surgery.Many patients come in to correct poor outcomes from their initial surgeries. The most common problems are due to implant malposition, bottoming out of the implant, poor scarring, and incorrect implant size.While the type of revision required will depend on the result of the previous surgery and the desired result of the patient, some revisions involve extensive pocket repair that may or may not need specialized external bras.Breast implant type and sizing selection is a complicated process and requires a detailed consultation that includes a discussion of your goals, a detailed examination, and a lengthy discussion. But the decision will always start and end with the patient. When it comes to sizing, we have all of our patients find 3 photos of their desired breast size. We ask for naked breast photos because clothing can obscure the true size (push up bras). Next, we consult with patients and go over the photos and take detailed breast measurements during a physical exam. Next, we using a sizing algorithm to determine a range of implants that will work based on the exam and the measurements.Lastly, during the operation, we use silicone sizers in the operating room to see how the size actually looks in the breast. We sit the patient up in the operating room, while asleep of course, and compare the sizer result with their desired look photos. If it is too small, we start the process over with a slightly larger implant. We don't stop until we get the perfect match.Of all of my breast augmentation patients, every one of them has been happy with their size due to this detailed and meticulous process. You don't want to invest time and money into a result that is either too big or too small.If you are considering breast surgery revision, you should speak with a board certified plastic surgeon and have yourself properly assessed. Only after a thorough examination you will get more information and recommendations. Also, you have to make sure that your surgeon understands your breast augmentation goals.Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery