I recently had a breast reduction & my nipples have fallen off. My doctor said they would grow back. Is that true? (Photo)

Thank you for your pictures.  Your breasts and nipple/areolar complexes unfortunately look normal for a free nipple graft.  I no longer perform free nipple grafts  with my experience I have been able to use a superior-medial pedicle to preserve the nipple or reconstruct the nipple at the time of the reduction.  Free nipple graft cosmetic results are poor in my opinion due to the variation in the return of the pigmentation and loss of nipple projection.

Based on your photos, it appears your nipples have had some superficial sloughing. This is where the outermost portion of the graft falls off. As long as the underlying tissue survives, the nipple is actually still there even though some of the pigmentation may be lost. In my experience, this pigmentation has largely returned over the first 6-12 after surgery. If it does not completely return, tattooing may be an option to even out the pigmentation as well.

After free nipple grafting, some of the skin graft may become discolored, dry, infected, or fall off.   Once the area has healed, if pigment changes persist, then the area can be tattooed.   Additional procedures can be performed to reconstruct the nipple/areola complex.  But, nipples do NOT grow back. 

Given your breast size and the procedure necessary for the reduction, nipple slough is a well recognized consequence in many women, Either grafting or tattooing would be necessary to restore the nipple areolar complex.  In terms of differences in breast sizes, this could still be based on swelling so give it time but continue to discuss with your surgeon.