Definition: Nipples that do not protrude but are sunken inward are called nipple invagination. In true nipple invagination, the nipple does not protrude when the areola is squeezed (see picture) Hazards: 1. The secretions from the inverted nipples cannot be discharged and can stimulate the ducts to produce periductal inflammation, which is one of the causes of “plasma cell mastitis”. 2, nipple inversion seriously affects breastfeeding. The inversion of the nipple seriously affects the baby’s sucking, making breastfeeding difficult. The milk can not be discharged in time can still cause the accumulation of milk, and even mastitis. Treatment: 1. Conservative treatment: manual pulling, suction therapy, etc., has a certain effect on mild nipple invagination. Surgery: For severe nipple invagination, it is the only method. (1) stent method nipple invagination correction So far, this method is the only surgical method that can preserve the function of lactation (see figure), the sunken nipple is fixed to the external stent by steel wire, after 3-6 months of continuous pulling, to achieve the purpose of lengthening the nipple and correcting nipple invagination. This method does not require an incision in the skin, does not destroy the milk ducts, can preserve the function of breastfeeding, and also does not affect the sensation of the nipple, and has a low recurrence rate. The disadvantage is that the treatment time is longer and may cause inconvenience in life. (2) Incisional nipple inversion correction This method can be used for women who have given birth and are not considering breastfeeding in the future, or for patients with recurrent local inflammation and severe concave deformity from scar pulling. During the operation, the breast ducts are completely cut off, the sunken nipple is fully released, and tissue flaps are designed to fill the tissue defect at the root of the nipple to strengthen the support of the nipple. However, the incision method requires dissociation or partial dissociation of the breast ducts, which affects the postoperative lactation function; if the scar on the deep side of the nipple develops contracture, it can cause recurrence of nipple invagination.