Clinical Assessment of Skin Tightening and Contour Change of Submental Tissue Using Bipolar Radiofrequency Microneedling
The aging process of human skin is characterized by a thinning of the dermis, atrophy of the extracellular matrix, and reduced collagen synthesis. Loss of collagen in the dermis is an aesthetic concern, as it is the main structural support in the dermis. Its loss, therefore, results in skin laxity. The use of non-invasive and minimally-invasive aesthetic treatments to reduce signs of aging has gained increasing popularity. Devices utilizing several different types of energy have been developed, including laser, radiofrequency, and ultrasound. Bipolar fractional radiofrequency devices use microneedles and a controlled thermal injury to stimulate neocollagenesis and neoelastosis. The purpose of this study was to evaluate the safety and tolerability of a bipolar fractional radiofrequency device on submental tissue and its effect on skin tightening and contour change.
Methods/Technique:
This single-center, unblinded, non-randomized study enrolled 15 qualified and consenting subjects between the ages of 21 and 70 years old. Exclusionary criteria included, but was not limited to immunosuppression; use of anticoagulants; history of photosensitivity; pregnancy or nursing; excessive skin laxity; scarring, tattoos, metal implants, or open wounds in the treatment area; use of oral retinoids or corticosteroids within the past 6 months; arrhythmias or other significant cardiac history, including pacemaker implantation; radiation therapy in the treatment area; or any skin pathology that could interfere with treatment or evaluation. After receiving a local anesthetic of 1% lidocaine with epinephrine 1:200,000, each subject received one bipolar fractional radiofrequency microneedling treatment (Candela Medical Ltd., Wayland, Massachussetts) to the submentum. Subjects followed up three- and six-months post-treatment. At every visit, standard and 3D photography were performed. Non-invasive measurements, including transepidermal water loss (TEWL), high-resolution ultrasonography, optical coherence tomography (OCT), and BTC-2000 were also taken. Finally, microbiopsies, 0.33mm in diameter, were collected in the midline of the submentum at the treatment and two follow-up visits. During the treatment, subjects were asked to assess their level of pain on an 11-point scale. Blinded photo evaluations were performed by three physicians, who were subsequently unblinded to assess any observed changes using the Global Assessment Improvement Scale (CGAIS).
Results/Complications:
All subjects experienced pinpoint bleeding at the microneedle insertion sites during the treatment, but it was ensured that any bleeding had ceased before subjects left clinic that day. Erythema, edema, and bruising was noted in all subjects post-treatment, with average scores of 2.63, 2.00, and 1.88, respectively, on a scale of 0 (None) to 4 (Extreme). However, all of these reactions are anticipated and subjects reported that they resolved within days or up to 2 weeks post-treatment. No burns, crusting, hypo- or hyperpigmentation, or any unanticipated adverse events were noted in any subjects either during treatment or in the follow-up phase. Patient comfort during treatment was also high, as the average pain score reported with use the of local anesthetic was 2.0 out of 10.
Using the Markerless Tracking feature on the H2 3D Imaging System (Canfield Scientific, Parsippany, New Jersey), skin surface changes and volume difference of the submentum were calculated, demonstrating a statistically significant contour change after the single treatment. The three evaluators noted a clear improvement in the appearance of the submentum, both based on blinded photo evaluations and CGAIS scoring. Additionally, the microbiopsy samples were used to correlate changes seen in the non-invasive skin measurements with histology and gene expression. The levels of extracellular matrix proteins, such as collagen, elastin, and hyaluronic acid, were measured and compared between baseline and the follow-up visits, as well as the relative expression of inflammatory markers.
Conclusion:
The results from this study illustrate the safety and tolerability of a single treatment using a bipolar radiofrequency microneedling device to tighten submental tissue. Both non-invasive skin measurements and microbiopsy data demonstrated objective changes in skin architecture after treatment. The treatment was well-tolerated among all subjects, with only minimal discomfort reported after injection of a local anesthetic. Though subjects experienced mild to moderate erythema, edema, and bruising as a result of treatment, these side effects were anticipated and resolved within 2 weeks of treatment. There were no adverse events related to either the device or the treatment throughout the course of the study. Additionally, 3D imaging demonstrated a significant lift and contour change within the treatment area. Further studies may evaluate a larger sample size or the feasibility and tolerability of this treatment on other regions of the body.