Breast implants aren't one size (or even one shape!) fits all. They come in a wide array of sizes and shapes, to ensure that you get an implant that gives you the most natural and ideal look for your breasts.
There are several factors to consider when you're choosing the shape of your breast implant, including the amount of breast tissue you currently have, your current breast shape, and where you're placing the implants (whether it's beneath the muscle wall or not).
There are two main breast implant shapes: round and teardrop or contoured shape. But there are pros and cons to each type of breast implant. You should consult with your plastic surgeon and consider your own preferences to help you select the right shape of breast implants for you.
Round Breast Implants
Round breast implants are the most common — and often least expensive — breast implant shape. These are perfectly spherical, so there's less concern about slipping or flipping of the implants than with contoured breast implants, and a smaller chance of developing complications or issues. But in some women, their perfectly spherical shape (especially if filled with silicone) can make it look more "fake" than the more natural anatomical breast implants. But in others, the round breast implant's tendency to move more naturally with the body, including lying flat when you're lying flat, may make breast implants appear less obvious — especially if they are placed beneath the chest muscles.
Teardrop Breast Implants
Contoured or anatomical breast implants more closely mimic the look of natural breasts, with a wider shape at the bottom that rises to slimmer profile at the top, forming a teardrop shape. They were initially created for use in women who were having breast reconstructions after a mastectomy, but they can also be a good choice for women who are simply getting a breast augmentation to improve the size and shape of their current breasts. An anatomical breast implant will also maintain the same teardrop shape whether you're standing or lying down, unlike a natural breast that shifts shapes, which can make the breast implants more obvious.
The outer shell of these contoured breast implants is textured to make it harder for them to slip out of place or flip over, which could lead to unnatural-looking, misshapen breasts. But that won't necessarily prevent them from moving out of place — and because of their tendency to flip, there are some plastic surgeons who refuse to use anatomical breast implants.
Your plastic surgeon will be able to review your needs as far as breast size and shape, and make a recommendation of the best breast implant shape for you.