Breast Implants for Stretching out Tight Breast Skin?

Their are varying degrees of contricted breasts. Skin can always be stretched but your condition amy be due to a limited or constricted breast mound. This sometimes benefits from the use of radial relaxing incisions performed at the time of breast implant placement.

Every situation is unique and I can't comment on your issue specifically without more information. However, I do often see patients who have tight skin which makes it impossible to put an implant of the desired size in. A good solution in these cases is to use an expander implant called Spectrum, from Mentor. The way it works is the implant is only partially filled at surgery. There is a tube entering the implant which goes to a "fill port" which is under the skin below the breast. Every few weeks some additional saline is put into the implant through the fill port until the skin is stretched enough and the size and shape is achieved. The port is then removed under local anesthesia.
Pictures here (last set on the right): http://www.drbaxter.com/breast_augmentation.html

In general, the soft tissue which includes the skin overlying the breast implants will “stretch out” over time. In fact, we usually advise our patients that their optimal results following a breast augmentation is not appreciated until 3-4 months after their surgery. How this will personally impact you is definitely dependent upon your physical features and the size/shape of the breast implants to be used. You need to be evaluated.
I would advise that you schedule a consultation with a board certified/eligible plastic surgeon to perform a thorough examination and provide you with the appropriate information.
I hope this helps.

I'm not sure what you're referring to. A little too vague. But skin will stretch with an implant under it. This is analogous to a tissue expander. However, there can be varying degrees of tubular breast or other breast deformities. So just be aware that you may need to have some glandular work done as well as the implants.

Without examining you it is difficult to give you a definitive answer.  If the lower pole is tight, you may have a tuberous breast which may require additional maneuvers during surgery.   If you are just very flat, an implant will usually stretch it out evenly.