Is it possible for the submuscular pocket to be too small?

It is rare but can happen. I wish you the best of luck. Vasileios Vasilakis, MD. Double board-certified, fellowship-trained plastic surgeon, Houston. TX.

Dear watmoetje,
generally speaking, your anatomy can limit the size of pocket and implants. 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

For most patients the surgeon is able to create a pocket wide enough to place the agreed upon implant. However in some patients the anatomy can limit the pocket size created. This is sometimes seen in very petite women.

Yes, in very small women, we are limited in how much we can stretch the pocket. There is more stretching of tissue in front of the muscle than behind. Otherwise, you wind up with tight balls on your chest.