Do I go bigger? I have 315cc LP teardrop under the muscle. Should I go up to 490cc? (photos)

Hi, thanks for your question - this is a common dilemma for many patients.  
Looking at the photos you show, I would say you have a good shape and a nice size already so you must think very carefully about the value-added of having further surgery compared to the expense and potential risks of operation which you will be exposed to all over again.  Heavier implants probably will stretch the breast more with time so you are more likely to commit yourself to the need for further operations in the future, e.g breast uplift and, although the data is not entirely consistent, it is probably the case that breast encapsulation is more likely with bigger implants.
remember also that humans perceive change as a proportionate effect, so, when you had your 315 implants in your 'a' cup breast, you probably doubled or tripled the size of your breasts (100-200% increase).....this time, by adding a further 175cc of size, you will go through approximately the same operation and costs but your breasts will only be enlarged by, perhaps a quarter (25% increase).
so, you should be ok with all these issues before committing to a further op.
best wishes

Dear keykey14,
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.You should discuss your concerns with a board-certified plastic surgeon and make sure that your surgeon understands your goals.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

There are many factors (besides just implant volume and profile) that come into play when it comes to the final "look" achieved with revisionary breast surgery.  
 In my practice, I find that pre-operative communication is the most important key when it comes to achieving aesthetic outcomes that patients are pleased with.  I ask patients to avoid using  potentially subjective terminology such as "C or D  cup", "natural or fake look", "significantly bigger", "1 cup size larger"…  On the other hand, the use of goal photographs and computer imaging (when possible) may be very helpful.   I evaluate all of the patient's "visual aids" that the patient is using to make sure that she is consistent;  otherwise fine tuning of the patient's goals is necessary, prior to proceeding.   The use of the visual aids also allow for discussion of realistic expectations; for example, there are times when a patient's anatomic starting point limits her ability to achieve her desired outcome safely.
   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. 
Again, in my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful.  
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 and after making the breast implant capsule adjustments). 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.
I hope this helps. Best wishes.