Thanks to ongoing refinements with radiofrequency (RF) and ultrasound-based contouring modalities, these treatments are becoming more versatile and patient-friendly, according to experts at the Cosmetic Surgery Forum, which took place in Las Vegas in December 2010.
In the ultrasound category, the Ulthera device, delivering a treatment called Ultherapy, is the first and only device cleared by the Food and Drug Administration for noninvasive brow lifting, says Curt Samlaska, M.D., assistant professor of medicine (dermatology), University of Nevada School of Medicine. It uses focused ultrasound waves working at a frequency between 4 mHz to 7 mHz to deposit very precise thermal coagulation points at depths measuring 3 mm to 4.5 mm below the skin's surface (White WM, Makin IRS, Barthe PG, et al. Lasers Surg Med. 2008;40(2):67-75. Laubach HJ, Makin IR, Barthe PG, et al. Dermatol Surg. 2008;34(5):727-734).
"Ninety-five percent of the energy is focused within a very small area. Only 2.5 percent of the energy is transmitted above the treatment zone, and 2.5 percent is transmitted below," Dr. Samlaska says. "The unfocused sound-wave energy is so minimal that there's no risk to the epidermis or deeper structures." As a result, he says, the device is colorblind. "You can treat the darkest skin without worrying about postinflammatory hyperpigmentation."The Ulthera device is also unique in that ultrasound waves not only provide treatment energy that contracts and lifts tissue; ultrasound imaging also allows physicians to visualize tissue as they are treating in real time, Dr. Samlaska says.
"No other device allows you to directly visualize your treated areas," he says, adding that the device's precision is also unparalleled. "Radiofrequency heating is more diffuse, so it impacts a larger area and is less well-controlled. And RF treats only the dermal layer. Ulthera is the only device that can target deeper regions such as the superficial aponeurotic layer, which is what plastic surgeons tighten in a traditional facelift. Now, for the first time, we can treat that layer without cutting into the tissues and undermining beneath it."
With some RF devices, Dr. Samlaska says, aesthetic physicians may worry that heating tissues will destroy fat, resulting in an unintended loss of facial volume. "That's what's great about Ultherapy — with precisely placed microfocused ultrasound combined with the ability to visualize the superficial aponeurotic layer, we can target it with very precise pinpoint energy without affecting intervening tissue. So we don't have to worry about fat necrosis with Ultherapy," he says.