Why not fully rounded out on outer sides? (Photo)

Dear mrsamrocz,
I understand your concern. However, without a proper assessment, it would be difficult to determine what went wrong. It is best that you visit your plastic surgeon for further assessment or ask for a second opinion. Only after a thorough examination, you can get proper recommendations and advice.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

The obvious reason may not be the true reason, so I would suggest discussing this with your surgeon. Also, check your before photos to see how flat your natural breast is in that area.

If one's breasts are not fully rounded out at five months, there may be a number of reasons. Sometimes, it just takes a little bit more time. Rounding out may take up to a year or longer. There can also be technical reasons for that, especially with submuscular silicone gel implants if the pocket is not completely opened up in this region. A moderate profile implant is quite soft and malleable. Some of the more firm implants do a better job at creating roundness on the bottom of the breast. The most important thing to do at this point in time is nothing. It would be appropriate to wait until nine months or a year postoperatively to see how they are looking. There is a chance this may need to be corrected although this can often be performed relatively simply. Have a good discussion with your plastic surgeon regarding your concerns. He or she may have other details with regards to your particular anatomy or situation that they can review with you.