- Loss of volume. Breasts change size with puberty, pregnancy, and changes in weight. They may actually be smaller, or they may just appear smaller (see #2 below).
- Ptosis. This describes the actual droopiness of the breasts. Medically speaking, there are three grades of ptosis. In grade I ptosis, the nipple is at the level of the inframammary fold (the skin crease below your breast). In grade II ptosis, the nipple is below the inframammary fold. In grade III ptosis, the nipple is at the lowest point of the breast. Severe ptosis can make a breast appear smaller because all of the volume is spread out, and sitting lower on the chest wall than it should be.
It is possible to have only volume loss, only ptosis, or a combination of the two. If the only problem is lost volume, then a breast implant will correct this by filling out the excess skin. If ptosis is the issue, then the treatment is a mastopexy. This involves an incision at least around the nipple. For more severe ptosis, the incision may be extended down the breast and even along the inframammary fold, similar to the anchor style incision used in breast reduction. Moving the breast tissue back where it belongs will make the breasts appear fuller. If volume is still deficient, however, then a breast implant may be needed in addition to the mastopexy.
Mastopexy and breast augmentation is frequently done as a single operation, if the ptosis is fairly minor (e.g. grade I ptosis). But correction may require two separate stages if the ptosis is very severe (e.g. grade III ptosis). This is because a mastopexy has the goal of lifting the tissue, but adding an implant at the same time adds weight. This added weight can compromise the results of the mastopexy, leading to a less optimal result than if the mastopexy is done first and the tissue allowed to fully heal before placing the breast implant.