Are Silicone HP Implants Wider/More Diameter Than Saline of the Same CC Amount?

If you have the same person implanted with Saline 450 implants behind the muscle and then have the same person implanted with 450 Silicone HP behind the muscle, will the silicone implant hand lower, have more diameter/width? Dr's say you lose 50 cc when switching to silicone form saline, but I feel Silicone appear larger because the hang, width and diameter appear larger in silicone. Am I correct in thinking this?

Doctor Answers (4)

Saline vs. Silicone implant dimensions


Some of the responses below indicate that dimensions are similar between saline and silicone implants, when in fact there are differences. For example, a Mentor HP 380 cc saline implant filled to 450 cc has a diameter of 11.4 cm and a projection of 6.4 cm. A mentor HP 450 cc silicone implant has a diameter of 12.8 cm and  projection of 5.1 cm. As you can see, the differences can be significant. You can go to the Mentor or Allergan breast implant pages online to see the dimensions for yourself. Because silicone implants can have a "softer" or "more natural" appearance in some patients than saline, the silicone may not look as full or large as the saline does of the same volume. Projection tends to be lower for silicone implants. When changing from saline to silicone implants in patients who want to keep the same overall size appearance and fullness, I typically use a slightly larger silicone implant, and generally not a lower profile implant (I use high or moderate plus for silicone in those cases).

Orange County Plastic Surgeon
5.0 out of 5 stars 16 reviews

Implant variations


Breast implant come in different base diameters and projection.  You should examine each implant as each one is designed for a different purpose.  The Vectra 3D imaging system is a good tool to evaluate how implants of various base diameters, volume and projections will look on you.  

Jeffrey Zwiren, MD
Atlanta Plastic Surgeon
5.0 out of 5 stars 10 reviews

Silicone and saline implants of the same projection have the same dimensions.


Breast implants come in different sizes and projections. Silicone and saline implants have equivalent dimensions when they are matched in size and projection.

Vincent N. Zubowicz, MD
Atlanta Plastic Surgeon
4.5 out of 5 stars 11 reviews



By-in-large the measurements of the implants is close to identical for silicone and saline implants of the same stated volume.  At 450 cc the difference for Allergan and for Mentor is about 2 millimeters of diameter.

Some surgeons feel that silicone implants placed under the muscle flatten out a bit more than saline and suggested slightly higher volume, but this is not a universally held opinion.

Jourdan Gottlieb, MD
Seattle Plastic Surgeon
4.5 out of 5 stars 34 reviews
