The breast changes as a result of aging, weight, fluctua-tions in weight, pregnancies, and breastfeeding. Sagging of the glandular body, breast envelope, and the nipple—areola complex (NAC) normally occurs synchronously and is described by Renault's Grade I to III ptosis classification. This classification describes the changes seen in the majority of breasts. The length of the thorax and the height of the SMF are, for the most part, not taken into account. Thus only absolute measurable parameters such as the distance of the nipples from the sternal notch provide signs of changes that are regarded by the observer as harmonious (“pleasing to the eye”) or disharmonious.
Changes to the three criteria, glandular body, envelope, and height of the NAC, may occur asynchronously, although this is not frequent. This typically results in pseudoptosis and glandular ptosis or sagging of the breast following surgery (bottoming out).