Nerve damage in nipple? 1 year post op. Saline under muscle.

Sometimes women will have sensation changes after surgery that are permanent. Although rare they may experience numbness of the nipple or breast. The surgery usually doesn't affect your nipple becoming erect, that may be related to other issues 

Thank you for your question and congratulations on your surgery!  After an augmentation the nerves of the skin are stretched as a result of swelling and the increased volume of the implants.  This stretching irritates the nerves which can cause a number of different nipple and breast skin sensations including increased/decreased sensitivity or a burning/electrical feeling.  These normally resolve spontaneously given enough time.  At over a year 16 months after surgery this is unlikely to change and the lower areola findings are likely due to this.  Hope this helps. 

In the majority of cases, the cause of nipple or skin sensory loss is unclear. I may be due to swelling or stretching of the tissues.

Loss of sensation may occur following breast augmentation. This is mainly due to a traction injury that is imposed on the branches of nerves that provide sensation to the nipple areola complex. In most cases this loss of sensation improves up to a year. If loss of sensation persists then it is likely to be incomplete or spotty as you are discribing. Larger sized implants seem to be more commonly associated with this outcome. Time may to be the only contributor to the outcome related to loss of sensation.