Why do doctors measure breast width diameter different ways?

Thanks for your inquiry.  Every doctor has different ways to assess
their patients and choose the right implant sizes.  It is not uncommon to have 3 different measurements
from 3 different plastic surgeons.  Some
doctors are very diligent about sticking to the numbers of the base width
diameter and others a little bit more liberal with it.  So, I would not focus on the actual numbers,
I would focus more on the results you are looking for and whether or not your
doctor can achieve those results.  One
way to do this is to look at the doctor’s before and after photos and find
photos that are similar to your build. 
Then, look for results that look similar to what you want.  I hope this helps. 

Many different surgeons have different techniques for surgery, as well as different techniques for measuring breasts and the pre- and post-operative care of their breast augmentation patients.  Similar to the phrase "there are many ways to skin a cat" (which, by the way, is a horrible saying if you think about it), there are many ways to end up with a great result from breast augmentation surgery.  If your surgeon is experienced and has a great reputation, has good results and you have a great rapport with her or him, then you should be confident that they know what they are doing in their particular method.Best wishes, Dr. L

Every surgeon has their own technique. What is most important is that it's consistent and reliable for them. The width of the breast determines the diameter of the implant that will be used. Good luck with your upcoming surgery.