Thank you for a great question. Unfortunately, there is not a cut-and-dry answer to this one, since there are no studies I am aware of to address this. I rely on ThermiSmooth and their new device Thermi250 for many applications in my office. For patients who are concerned about the theoretical risk of loss of facial fat, I ONLY use the smallest head or the bipolar attachment, as I know those heads will not penetrate deeper than the skin or dermis. The larger the diameter of the head, the deeper the penetration into tissue and the larger heads do cause some shrinkage of the fatty layer. To date, I have not had a patient lose facial fat volume as a result of using the more superficial ThermiSmooth or Thermi250 treatments, so my gut feeling is that you should experience facial fat reduction if the smallest head or the bipolar head are used, but, again, this is not based on a formal study, but only my own clinical experience.