Thank you for your question. This is a simple matter of the compression of your abdomen against her chest wall when sitting down which reduces some of the gravitational fall of your breasts and can make them look larger when sitting down.
Rest easy. It would be hard to tell the difference between the two. If there was a difference it would not show up in your clothing. Normally, if a patient wants to looked noticeably different in their clothing it is necessary to increase the implant volume by at least 30%.
It is very unlikely that you would notice any appreciable difference between breast augmentation performed with 285 cc moderate profile implants versus 300 cc high profile implants. Normally the patient comes in with implants in place and wants to appear noticeably larger in her clothing and...
