Breast implants for a 13 cm wide chest
I might measure you differently, but if you legitimately have a 13 cm base dimension you would look bad with an implant less than 12 cm wide. If you went down to a 10 cm implant you will look like 2 tennis balls separated by a freeway.
If you consider that the implants are discs and that the nipple should be about in the middle of the disc you should estimate how far up from the nipple you want the implant to go. Lets say that is 6 cm. That means that you would want an implant that has a 12 cm width.
If you chose a high profile implant with that base you would have a much higher volume and projection(something that you do not want) If you chose a moderate, it will give you the most width for size so it would be the smallest volume. A moderate plus would be somewhere in between.
It is very important to communicate your size goals with your surgeon. 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 “C cup” or "fake looking" 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.
I use intraoperative sizers and place the patient in the upright position to evaluate breast size. Use of these sizers also allow me to select the press implant profile (low, moderate, moderate plus, high-profile) that would most likely achieve the patient's goals. The patient's goal pictures are hanging on the wall, and allow for direct comparison.
I have found that this system is very helpful in improving the chances of achieving the patient's goals as consistently as possible.
By the way, the most common regret after this operation, is “I wish I was bigger”.
I hope this helps.
If you have deflated breasts and want to fill them out completely without being too big, then a moderate size implant usually would achieve that goal. I tend to recommend a moderate size implant for patients who want to achieve a natural look, with good upper pole fullness and cleavage.
Implant diameter and breast diameter with augmentation or enlargement
To get the smallest implant with the greatest diameter, select and implant that is a moderate profile. This will have the least projection but should be able to accomodate your BWD.
Implant choice for a small improvment in fullness
If you do not want a large change then you are probably better off with a moderate profile implant. Usually they are sized to be close to yoru BWD of the breast. I would go over this carefully with your surgeon.
Base diameter and Implant size
You should have a detailed discussion with your plastic surgeon about the choice of implant.
Without personally seeing you, only general advice can be given, but here are a couple of things to know: The measured base diameter is external, so the implant diameter has to be less than that to account for the thickness of the breast tissue, fat layer, and muscle.
This seems obvious but the implant diameter depends on the thickness of the tissue as well as the BWD for that reason.
For example if the thickness is 1.5 cm on each side then a 10 cm implant diameter could work. You will most likely want a low-profile implant to minimize volume gain but still fill out the BWD.