What implant should I get for a natural but full look? 500cc too big? Motiva vs Mentor? (photo)

Choosing an implant size/style is an important decision which is best made in concert with your surgeon. Ultimately, options are based on a number of factors including:
-Chest dimensions: This point is crucial as the width of your breasts defines the available "real estate" on which the foundation of your augmentation is built. This "foot print" is the absolute limit with which you are dealing. Too "large" is not so much the risk as too "wide." You cannot build a 3 acre mansion on a half acre plot. An implant which is too wide (exceeding the available space on your chest) will generally over hang laterally making it more noticeable and occasionally contributing to discomfort and nerve symptoms (numbness or tingling). This will also contribute to a more unnatural look.
-Tissue quality: This relates to size in the sense that the implant will be suspended by your tissue. Too large an implant may place took large a stress on these suspending tissues leading to healing problems in the short term and bottoming out in the long term.
-Patient desire (what is the look you are hoping to achieve?)
My role as a surgeon is to manage expectations and guide you towards a prudent choice which can satisfy these reasonable goals. Often times, a surgeon can guide a patient toward a size/cc range and patients will make determinations on implant style/profile. Patient seeking more or less projection, or seeking a more pronounced or subtle upper pole volume increase can be guided toward an implant which will help them best achieve their goals. Additionally, technique variations (sub muscular vs. sub glandular) can also aid in obtaining the look you desire.
There are a number of tools available to help guide patient/surgeon decision making including sizers, 3D imaging and goal photos. Each modality can help better communicate your goals to your surgeon and vice versa.
Ultimately, it is important to not marry oneself to a particular "cc" as oppose to a particular "look." Communication is key as you and your surgeon create your custom surgical plan.
Based upon your photos and stated desire for a "natural" look, I would recommend conservative sizing. While "natural" can mean many things to many people, larger high profile implants rarely meet this criteria in more petite individuals. I would recommend looking in the 300+ ml range.
As always, discuss your concerns with a board certified plastic surgeon.

Hi, of course for exact decision your body measurements should be taken but according to your pictures I have to state that the 500 is too big for your frame. I wouldn’t go over 350 cc in your case. In my opinion it won’t look natural also will increase the complication rate. About the implant brand, both are reliable implant. There are no major differences between them but I prefer use Mentor, as it sits perfectly under muscles.