Which is Better for Dense Breasts, Implants Placed Under or over the Muscle?

I think it is in your best interests (and that of most patients seeking breast augmentation surgery) to have implants placed in the “dual plane” sub muscular position.  This positioning allows for more complete coverage of the breast implants leading to generally more natural feel/look  of the implants in the long-term. This position will also decrease the potential for rippling and/or palpability  of the implants (which may increase with time, weight loss, and/or post-pregnancy changes).



The submuscular positioning  also tends to interfere with mammography less so than in the sub glandular position. The incidence of breast implant encapsulation (capsular  contraction)  is also decreased with implants placed in the sub muscular position.
  

The sub muscular (dual plane) breast implant positioning does have the potential downside of “animation deformity” ( movement/ distortion of the breast implants  seen with flexion of the  pectoralis major muscle).
 

Again, I think the advantages of sub muscular (dual plane) breast implant placement far outweigh the  potential disadvantages associated with breast implants  placements of glandular position,  no matter how "dense" the patient's breast tissue is.

I hope this (and the attached link) helps.

I am curious as to what is your goal? larger breasts? better shape? better position? Placing this size implant into D cup breasts will likely increase your size by several cup sizes. The concern is melding large breasts with large implants. It's tricky to get a natural union of the two structures. Going that large in size can cause disproportion of your figure so be careful. Most women do not want to look heavy and implants that large could cause you to look overweight. Sometimes D cup breasts can look fuller with a "lift" rather than an implant. If superior pole fullness is the goal, a lift with small implant can often achieve that.
So exact position of implant, and I do not recommend textured or a shaped implant, it is less important than size and shape. But my preference would be, without seeing you, sub muscular.