Dear Galore in Jeffersonville, IN:
The projection of the nipple depends on two things where it is and how big it is.
Most commonly an inverted nipple is a normal nipple that is tethered to the deeper structures. This tethering pulls the nipple back into the breast. So this otherwise normally shaped nipple lacks projection because it is in the wrong location, i.e., pulled down into the breast.
A nipple can also lack projection because it is small or flat. This can occur with out without the nipple being inverted. When it occurs without nipple inversion it is easy to tell; however, nipple inversion can sometimes hide the fact that the nipple is also flat. It only becomes apparent after the tethering is released, and at that point the surprise of having a flat nipple can lead to disappointment.
A non-functional nipple can be reconstructed. This is a completely different operation from inverted nipple repair. Inverted nipple repair is performed for a normal nipple which is hidden in the breast. Nipple reconstruction is done when there is an abscence of a nipple. Most commontly this is done for breast reconstruction after a mastectomy where the nipple has been removed. If nipple reconstruction is done on a normal breast, it is unlikely that you would be able to breast feed. The procedure involves repositioning the skin on the breast to form a projection. I involves additional scarring and the reconstructed nipple may flatten again over time. Several techniques of nipple augmentation also exist, but these need to be discussed indetail on a case-by-case basis.
A link is provided with more information: