Until recently, the minimally invasive aesthetic market has focused on fillers and botulinum toxins, with lifting and tightening achievable only via surgical intervention. The introduction of the ThermaCool (Solta Medical) radiofrequency (RF) device made the idea of tightening using a nonsurgical approach a reality.
But what constitutes actual tightening, and is it a truly achievable endpoint with a noninvasive procedure?
This column aims to discuss some of the devices available for skin tightening procedures. Following ThermaCool — which was formerly known as Thermage ThermaCool — several other devices hit the market with claims of skin-tightening capabilities.
The most important thing to remember when evaluating "tightening" is that this is a very difficult parameter to measure. Essentially, all of the data are via patient satisfaction ratings and/or photograph assessment, which can be altered by even the slightest change in positioning of the patient.
Some leaders in this field have proposed using tattoos and measuring the distance between the markings both before and after treatments.
Although circumference measurement is occasionally employed to determine outcomes, a reliable quantitative and objective manner of measuring tightening does not yet exist.
With all noninvasive tightening devices, dramatic improvement is seen in some patients, but predicting those who will respond is difficult.
In general, patients exhibiting sagging relating to skin laxity and not excess fat are more likely to have positive results than other patients. However, having used some of these devices, we can say that many patients are extremely happy with their cosmetic improvement and do experience significant clinical improvement with these procedures.
We've already touched on the ThermaCool device. Other RF devices include eMax (Syneron), Accent (Alma) and Aluma (Lumenis). Depth of heating depends on which form of RF is used: unipolar, monopolar or bipolar. To date, it is not scientifically determined which one of these will produce the best tightening effect.
With RF, heat deposited into the dermis potentially leads to collagen contraction, and later, collagen production. The exact temperature required to elicit a tightening response remains to be determined. The fluence delivered depends mostly on the patient's pain tolerance.
All RF devices are coupled with some form of cooling apparatus to protect the epidermis and minimize discomfort. With adequate administration of cooling, these devices are safe and can be used on any skin type. Various published studies suggest that these radiofrequency devices show promise in facial, abdominal, buttock and thigh tightening.
In one study, Tina Alster, M.D., evaluated the ThermaCool for cheek and neck tightening and found "significant improvement" in both cheek and neck skin. Patient satisfaction scores paralleled the clinical improvements observed. Side effects were mild and limited to transient erythema, edema and rare dysesthesia. No scarring or pigmentary alteration was seen (Alster TS, Tanzi E. Improvement of neck and cheek laxity with a nonablative radiofrequency device: a lifting experience. Dermatol Surg. 2004 Apr 30;(4 pt 1):503-507).
Light-based devices are also included in this market. Light devices use the same proposed mechanism of action as the RF devices: immediate collagen contraction with subsequent collagen production, via nonspecific heating of the dermis.
Most infrared devices heat into the dermis, but not very well into the fat. The lack of subcutaneous heating increases the safety profile, and the cutaneous depressions described with other tightening devices are not likely to occur with the infrared devices. The target chromophore of these infrared wavelengths is water, yet with long pulse deliveries, truly nonspecific heat is delivered.
The Titan (Cutera) light device emits a range of wavelengths from 1,100 nm to 1,800 nm. Its Food and Drug Administration clearance is for topical heating to increase local tissue temperatures and circulation, but in Europe it is cleared specifically for the treatment of rhytids.
The fluences delivered are based on patient tolerance, but they are usually around 40 J/cm2 . Heating of the dermis occurs at approximately 1 mm to 3 mm in depth. A cooling tip protects the epidermis by cooling pre- and post-delivery of pulse, as well as dynamic cooling during the actual heating. Collagen production can occur at any time up to six months post-treatment, so some patients continue to improve weeks after the treatment.
There is no downtime at all with these infrared treatments. However, immediate erythema is seen in the treated areas, and it may last a few hours. In addition, treatments are relatively painless — no topical anesthesia is required at all, and the safety profile is impressive. Two to six treatments are generally recommended. The authors of this column have not experienced a single complication at the University of Miami using the Titan device.