Does putting an implant under the muscle make it look smaller?

The short answer is: Yes, submuscular (under the muscle) placement can make implants appear slightly smaller–especially in the upper pole–compared to over the muscle placement. This is because the pectoralis muscle provides an additional layer of coverage, particularly in the upper chest which can subtly dampen the projection of the implant and make the transition look more gradual. For women with a smaller frame or limited natural breast tissue, under-the-muscle placement offers a more natural contour and helps to reduce the risk of visible rippling. However, the final look also depends on multiple other factors–implant profile, chest with, tissue characteristics, and surgical technique.
Dr. Brandon LambirisBoard-Certified Plastic Surgeon–Sarasota, FL

Your implant will probably have a softer margins and this may make it generally looks smaller. Because of this, patients may want to opt for a little bit more volume. The volume difference between the implants you mention is about the same volume of 4 tablespoons of fluid. Many people would not consider this much of a difference.

Yes, implants placed under the muscle can appear slightly smaller due to added tissue coverage, especially in the upper pole. The difference between 430cc and 485cc is about 1.8 tablespoons—noticeable to some, but not dramatic. If you're between sizes, most surgeons recommend going slightly larger to avoid regrets.

Dear RSMember12714,

I almost always place implants submuscular. It lowers the rate of capsular contracture significantly. In addition, it looks much more natural because the muscle provides covering over the implant so its not as round on the top. I've also noticed the implants drop less over time when they are protected under the muscle.

Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Since the implants are positioned partially beneath the muscle, the surrounding tissue may initially compress that area. As you heal and the tissue gradually expands, the implants should experience less compression, allowing for a more natural feel and appearance.

A difference of 55cc is small and is mildly visible. It would be a good idea to try on both sizes at your doctor’s office to see which you prefer.