What is considered a large breast implant? What is considered a wide chest? (photos)

Thank you for the good question.  Generally speaking, I do not think that it is helpful to individual patients to classify breast implants as "small or "large".  For example, 400 breast implants on a very petite patient may be too "large" whereas 800 cc breast implants on a bigger frame may be too "small". In other words, arbitrary statements such as "breast implants larger than 600 cc are considered large" are not helpful when it comes to clinical practice.
 What IS important: appropriate selection of breast implant size/profile to safely achieved patients aesthetic goals.  Ultimately, careful communication of your goals (in my practice I prefer the use of goal pictures, direct examination/communication in front of a full-length mirror, in bra sizers, and computer imaging) as well as careful measurements (dimensional planning) will be critical.
 Generally speaking, the best online advice I can give to ladies who are considering breast augmentation surgery ( regarding breast implant size/profile selection) is:1. Concentrate on choosing your plastic surgeon carefully. Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. ***Ask to see lots of examples of his/her work.2. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. For example, I have found that the use of words such as “natural” or "C or D cup" etc means different things to different people and therefore prove unhelpful.Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup size may also be inaccurate. Again, the use of computer imaging has been very helpful during the communication process, in our practice.3. Once you feel you have communicated your goals clearly, allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals. Again, in my practice, this decision is usually made during surgery, after the use of temporary intraoperative sizers.I hope this (and the attached link, dedicated to breast augmentation surgery concerns) helps. Best wishes for an outcome that you will be very pleased with.

"Wide" is a relative term based on your height and weight. Most consider large implants to start around 450 cc's. However, what is consider large on an individual is based upon their height, weight, and measurements. For someone who is 4'10", a 450 cc implant could be huge, but on someone 5'10", it could be proportional.