Hello, I'll offer a little update to your question. Ulthera, as stated in many of the earlier answers, allows a precise delivery of ultrasonically generated heat to the skin (especially the deeper dermal layer) and the deeper facial fascia (the layer just above the muscles of the face). One of the great things about this machine is that the operator can visualize the layer being treated with a real-time ultrasonic picture generated by the transducer. However, there is fat between the skin and the deep fascia as well as under the deep fascia. Could this fat be damaged by the heat energy? If the operator is well trained and understands the technology, I think there is little risk that the intervening fat can be affected, but there is a potential risk if the energy is not delivered correctly (the inappropriate use of the deep transducer in an area, or a misinterpretation of the ultrasound picture showing the depth of treatment). Damage the fat would likely be subtle and difficult to see, but in a thin patient it could potentially be a problem. Having said that, to date, we have not had any problems with loss of facial volume/fat due to Ulthera and consider it a very safe treatment.