Implant Shape in Breast Augmentation: Aesthetic Outcomes and the Ability to Distinguish Between Shapes

Objective: This study aimed to evaluate the impact of implant shape—round vs. anatomical—on long-term aesthetic outcomes in breast augmentation and to determine whether observers could reliably distinguish between implant types. Methods: Thirty female patients who underwent subpectoral augmentation with silicone gel implants (15 round, 15 anatomical) were included. All surgeries were performed by a single senior surgeon. Standardized preoperative and 1-year postoperative photographs were evaluated by 10 plastic surgeons and 10 surgical nurses. Observers identified implant type and, separately, surgical nurses assessed naturalness using a 4-point Likert scale. Statistical analyses included chi-square tests, independent samples t-tests, and Fleiss’ Kappa coefficients to evaluate inter-rater agreement. Results: Observers demonstrated limited ability to correctly identify implant type. Among surgeons, correct classification rates were 27.0% for anatomical implants and 26.3% for round implants, with an overall Fleiss’ Kappa of 0.110, indicating slight agreement. Nurses achieved similar results, with correct classification rates of 27.3% and 22.7% for anatomical and round implants, respectively (Fleiss’ Kappa = 0.126). Combined analysis of all observers yielded a total Kappa value of 0.040, suggesting classifications were largely random. Mean naturalness scores did not differ significantly between implant groups ($2.68 \pm 0.17$ vs. $2.68 \pm 0.15$; $P = .909$). Factors most frequently cited for “artificial” appearance included low nipple position, excessive upper pole fullness, and overall large breast size. Conclusion: Implant shape had no significant impact on long-term natural appearance or observer identification accuracy. These findings highlight that both round and anatomical implants can achieve comparable aesthetic results, with patient-specific anatomy and preferences remaining central to implant selection. Cite this article as: Demirel O. Implant shape in breast augmentation: aesthetic outcomes and the ability to distinguish between shapes. Cerrahpaşa Med J 2026, 50, 0078, doi:10.5152/cjm.2026.25078.