Background and Objective:: The radio-frequency (RF) device is a system capable of volumetric heating of the mid to deep dermis and selective heating of the fibrous septa strands and fascia layer. Clinically, these effects promote dermal collagen production, and tightening of these deep subcutaneous structures. A new technique of using multiple low energy passes has been described which results in lower patient discomfort and fewer side effects. This technique has also been anecdotally described as giving more reproducible and reliable clinical results of tissue tightening and contouring. This study will compare ultrastructural changes in collagen between a single pass high energy versus up to five passes of a multiple pass lower energy treatment. Study Design/Materials and Methods: Three subjects were consented and treated in the preauricular region with the RF device using single or multiple passes (three or five) in the same 1.5 cm 2 treatment area with a slight delay between passes to allow tissue cooling. Biopsies from each treatment region and a control biopsy were taken immediately, 24 hours or 6 months post treatment for electron microscopic examination of the 0-1 mm and 1-2 mm levels. Sections of tissue 1 mmÂ1 mmÂ80 nm were examined with an RCA EMU-4 Transmission Electron Microscope. Twenty sections from 6 blocks from each 1 mm depth were examined by 2 blinded observers. The morphology and degree of collagen change in relation to area examined was compared to the control tissue, and estimated using a quantitative scale. Results: Ultrastructural examination of tissue showed that an increased amount of collagen fibril changes with increasing passes at energies of 97 J (three passes) and 122 J (five passes), respectively. The changes seen after five multiple passes were similar to those detected after much more painful single pass high-energy treatments.Conclusions: This ultrastructural study shows changes in collagen fibril morphology with an increased effect demonstrated at greater depths of the skin with multiple lowfluence passes and at lesser depths with single pass higher fluence settings. Findings suggest that similar collagen fibril alteration can occur with multiple pass low-energy treatments and single pulse high-energy treatments. The lower fluence multiple pass approach is associated with less patient discomfort, less side effects, and more consistent clinical results. Lasers Surg. Med. 38:150-154, 2006.

Greater densities of shallower damage columns at lower energies may better improve pigmentation, whereas deeper injuries, using higher energies and moderate densities, may better improve texture. This pilot study did not compare similar fluences and histologic damage between the two systems, and newer available systems allow for greater depth of penetration.

To compare the effectiveness of 1 and 2 radiofrequency (RF) treatments with the ThermaCool TC system (Thermage Inc, Hayward, Calif) on middle and lower face laxity. Methods: Twenty patients with mild to moderate laxity of the middle and lower face were randomly assigned to receive either a single RF treatment or 2 treatments spaced 1 month apart. Treatment energy levels were titrated to patient tolerance and ranged from 85 to 135 J/cm 2. Acute clinical response was recorded after each session. Standardized photographs were taken before treatment and at 1 and 4 months after the last treatment. Using a percentage scale, 4 blinded physicians experienced in dermatologic laser therapy independently rated improvement in nasolabial folds, marionette lines, jowls, laxity under the chin, and overall appearance. In addition, subjects completed quality-of-life surveys 1 and 4 months after treatment. Each patient paid the same fee for involvement in the study. Results: Eleven patients received a single RF treatment, and 9 patients underwent 2 treatments. All subjects experienced mild edema and mild to moderate erythema as an acute clinical response; no patients