110 lbs, 22 years, 5ft tall, small waist, bigger hips, currently a B cup, what would be the best size for my body? (Photos)

Hello dear!!
Thank you for your question and provided information as well..
Based on your photos, it seems that you have symmetrical breasts for which you wish to add more volume. There are many ways that plastic surgeons perform measurements in order to determine which breast implant size, style and shape will best suit your goals. It is important that you communicate to your board-certified plastic surgeon what are expecting, to make certain that your goals are realistic. It's helpful to show pictures of results you'd like, but please keep in mind that these are other people and your body is different from everybody. In my office, we use a method of sizing with silicone gel forms of known volumes. This is proven to be a very accurate means of determining what size will might be of additional interest to you as well.
Know that the size, profile, and shape of the implant is based on your desired breast size/shape, your chest wall measurements, and soft tissue quality.  This decision should be based on a detailed discussion with equal input from both you and your surgeon.   
Hope this helps and best of lucks.
Dr. Luis Mejia.

The most appropriate implant size for you really depends on the breast size and fullness you desire.  As a general rule, if you pick an implant that is no wider than your present breast diameter, you will look more natural because your own breast tissue will cover the edge of the implant.  So you need to consider the volume (size), the profile (projection), and width of the implant.  That said if you desire to be in the full B size range, I would choose a size in the high 200’s-low 300’s.  If you want to be a moderate to full C size, then choose a mid to high 300cc range.  Anything more would look very top heavy and place you in the D cup range.  I would suggest a mid 300 cc size, but you have to decide the look you are after.