Plastic surgeons aim to achieve breast symmetry during cosmetic and reconstructive breast surgery. They rely on measures of breast size, position, and projection to determine and achieve breast symmetry, but normative data on symmetry in preoperative breast reconstruction patients are scarce.
A statistical evaluation was performed to examine the relationship of breast symmetry to demographic and clinical factors such as age, body mass index (BMI), race, and cancer status in a sample population of 87 patients who were scheduled to undergo mastectomy and breast reconstruction. The sternal notch to nipple (SN-N) distance and breast volume were measured on three-dimensional images, and distance and volume ratios across the left and right breasts were compared to determine symmetry. Ptosis grades were recorded and grade agreement (match) across the left and right breasts was assessed to determine shape symmetry.
A substantial portion of women (41.4%) showed SN-N distance differences >5 mm and 50.6% exhibited a volume difference >50 mL between their right and left breasts. Multiple linear regression modeling did not show any association between age, BMI, and cancer status and the SN-N and volume ratios. Race showed an association with volume symmetry but not with SN-N symmetry. A higher BMI increased the likelihood of ptosis disagreement. Additionally, tumor size did not impact overall breast symmetry.
This study provides normative data on the extent of breast asymmetry in preoperative patients that can guide physicians in setting realistic goals for reconstruction procedures and manage patients' expectations related to outcomes.