Today, a growing number of people aspire to have a younger face and cosmetic surgery is becoming increasingly popular worldwide [1] . People are undergoing cosmetic surgery because of its positive effects on their social relationships [2] , body image [3] , and self-esteem [4] . Research has found that media exposure and conversations among friends over body dissatisfaction are related to attitudes toward cosmetic surgery [5] . Published recommendations and clinical evidence mostly reference Western, and not Asian attitudes to beauty addressing such ideas as structural facial anatomy and signs and rates of aging. Within the Korean population, having “normal appearance” is considered to be of critical importance and is strongly associated with the face of a person [6] .

Facial cosmetic surgery focuses on improving facial appearance vis-à-vis injectable fillers, neural modulators, lasers, and other treatments aimed at rejuvenating skin [7] . Practitioners and patients of traditional invasive surgery to remove facial wrinkles, pull up an elongated jawline, cut and exfoliate the skin, and transplant fat to a reduced facial fat layer, should take into account the possibilities of a long recovery time and health complications [8] . Therefore, approaches are on the rise to treat facial aging with minimally invasive treatments and include procedures involving botulinum toxin, filler, and thread lift [9] . Today, botulinum toxin injection is the most commonly performed nonsurgical cosmetic procedure in the world [10] [11] .

Traditional surgical intervention and ablative skin resurfacing have been performed to improve facial rhytids from skin laxity, although new methods have evolved that are less invasive and tend to minimize recovery time and risk of postoperative complications. The application of noninvasive radiofrequency (RF) treatment has been steadily increasing over the past several years to accommodate the paradigm shift in facial aging treatment to noninvasive [12] . Thermage control pulse technology (hereafter “thermage”) protects the skin surface by the delivery of radio-frequency energy to the dermis, which is known to clinically improve the tightening and contouring of the skin through collagen contraction and remodeling [13] . In 2002, thermage received U.S. Food and Drug Administration approval for treatment of wrinkles around the eyes and in 2004 was approved for treatment for all facial rhytids.

In clinical practice, a wide variety of treatments for the management of facial aging have been conducted. Patients normally have the option to receive one of these procedures or to combine procedures. However, there has been limited data analysis in general of the use of noninvasive RF treatments, and, more specifically of the relationships between the use of minimally invasive and more invasive treatments. This study analyzed the Korean population trends in treatments for the management of facial aging by year and age group exploring correlations between patient use of noninvasive RF and minimally invasive procedures.

Data were collected from chart records of outpatients who were treated from January 2013 to December 2017 for the management of facial aging. The charts of 9110 patients who visited a clinic for facial aging treatment during the study period were reviewed to narrow the study group to those 4201 patients who had been administered thermage (Thermage® Inc., Hayward, CA), Polydioxanone thread (PDO) thread lift, Silhouette Soft Thread (Poly-I-lactic acid or sculptra solid form), nasolabial fold filler, and botulinum toxin treatments for the masseter and lines of the glabella, forehead, and lateral canthus and fulfilled other criteria (age, gender, date of treatment, detail of treatment) important to the study. The ethical part of this study was approved by the Korean Public Institutional Review Board, which is designated by the Korean Ministry of Health and Welfare (report IRB No. P01-201808-21-013).

Statistical analyses were performed using SPSS 23.0 software (IBM, Somers, USA). The characteristics of patients who received facial aging treatment were summarized using descriptive statistics. Differences between the number of noninvasive RF treatments and minimally invasive treatments by year and age group were analyzed using t-tests and ANOVAs. In addition, a multiple logistic regression was performed of the relationship of the independent predictors of age, gender, year, and type of past treatment PDO thread lift, Silhouette Soft Thread, nasolabial fold filler, and botulinum toxin treatments for the masseter and lines of the glabella, forehead, and lateral canthus, with the general treatment class, being either noninvasive RF or minimally invasive. Data were presented as an odds ratio (OR) with a 95% confidence interval (CI). A value of p < 0.05 was considered statistically significant for all tests.

The general characteristics of the study subjects are presented in Table 1. For the 4201 patients, the mean age was 42.5 ± 9.6 years (range 20 - 81 years). The

majority of the patients were in their forties; 93.2% of the patients were women, and the overall number of patients increased by 42.5% from 2013 to 2017.

The type and number of facial treatments from 2013 to 2017 are presented in Table 2. The maximum number of treatments was 1400 for thermage followed by botulinum toxin treatments. Thermage treatments increased yearly, with a 134.9% growth from 2013 to 2017.

The type and number of treatments for the management of facial aging by age group over the five-year period are presented in Table 3. The 40 - 49 age group had the highest number of overall treatments, which included thermage, PDO thread lift, nasolabial fold filler, and botulinum toxin treatments for the lines of the glabella, forehead, and lateral canthus. The Silhouette Soft Thread treatment was the most common in the 50 - 59 age group, and the masseter botulinum toxin treatment was the most common in the 30 - 39 age group.

The type and number of minimally invasive thermage treatments are presented in Figure 1. The rate of patient use of each of the treatments of PDO thread lift, Silhouette Soft Thread, nasolabial fold filler, and the botulinum toxin treatments, was lower in patients who had received thermage treatment than in patients who had not received thermage treatment (p < 0.001).

The results of the logistic regression analysis of the relationship of the independent predictors in terms of the class of thermage treatment (noninvasive RF vs minimally invasive) are shown in Table 4. Overall, as age increases, patients tend to receive thermage treatment (p < 0.001). In addition, the > 60 age group used the thermage treatment more than the 20 - 29 age group (p < 0.001, OR = 7.866). For gender, women were more likely to undergo thermage treatment than men (p = 0.003, OR = 1.698). Based on treatment year, the use of thermage treatment by the patients was higher in 2016 and in 2017 than in 2013 (p < 0.001). Considering thermage treatment versus the other procedures, patients receiving the former were less likely to undergo the treatments PDO thread lift (p < 0.001, OR = 0.081), Silhouette Soft Thread (p < 0.001, OR = 0.063), nasolabial fold filler (p < 0.001, OR = 0.049), and botulinum toxin treatment for the masseter (p < 0.001, OR = 0.031), and lines of the glabella (p < 0.001, OR = 0.206), forehead (p < 0.001, OR = 0.309), and lateral canthus (p < 0.001, OR = 0.258).

As age increases, the reduction in skin elasticity due to facial aging creates wrinkles which become more prominent with time. For patients seeking to reduce these wrinkles, surgical facial plastic surgery treatments include brow lifting with an autologous fat transfer, face and neck lifting, laser resurfacing of the skin envelope, and chemical peeling [14] .

However, contemporary patients are looking for minimally invasive procedures using, for example, botulinum toxin, filler, and thread lift [7] . In the present study, the data show that the number of patients receiving noninvasive

X^a, X: untreated case; O: treated case.

X^a, X: untreated case; O: treated case.

and minimally invasive treatments in 2017 increased by 42.5% compared to 2013. Patients receiving thermage treatment increased by 134.9% during the 5 years, with the patient group aged 20 - 49 years receiving the most thermage treatments. A previous study in China also reported a striking increase in thermage treatment whereby patients aged 35 - 50 years accounted for the largest population taking advantage of this procedure [1] .

The noninvasive RF treatment minimizes the recovery time and risk of postoperative complications that are common with invasive treatment. The RF treatment is performed to treat tissue laxity in the periorbital areas, forehead, and middle and lower face. In previous studies, promising results of nonablative RF treatment to tighten tissue in the periorbital areas were reported. A multicenter study of 86 patients submitted to this treatment demonstrated measurable brow elevation and modest clinical improvement in periorbital rhytids in 80% of the subjects [15] ; another study showed improvement of lower eyelid laxity in 9 out of 9 patients [16] . A previous study reported that the middle and lower face laxity of patients who underwent two consecutive noninvasive RF treatment sessions was better than that of those who were treated only once [13] . In addition, previous studies have confirmed the efficacy of thermage treatment in facial aging management when used as a stand-alone treatment or in combination with minimally invasive cosmetic treatments, such as those that use intense pulsed light, nonablative lasers, neurotoxins, and fillers [17] [18] [19] [20] . However, in this study, patients who had received thermage treatment used other minimally invasive treatments less, such as botulinum toxin, filler, and thread lift, than those who had not.

Botulinum toxin injection, which affects muscular activity to correct upper face wrinkles, is most commonly performed clinically [21] . In the present study, results show that as age increases, the rate at which patients receive botulinum toxin treatment also increases. A previous study also found that botulinum toxin injection was the most commonly requested procedure in China, and that age was significantly related to the incidence of its injection [1] . However, in this study, patients who received thermage treatment used less botulinum toxin for the upper face compared to those who did not. This is likely because the group receiving the noninvasive RF treatment has a negative view of more invasive treatments such as botulinum toxin injection.

The nasolabial wrinkles that occur because of aging are a problem for many persons. There are two causes of nasolabial wrinkles: 1) defective muscle and skin defects caused by repeated skin folds, and 2) the downward migration of the malar cheek pads; however, the origin of nasolabial wrinkles in many patients is often mixed [22] . Many patients have considered filler treatment for this condition. In a previous study, patients who received filler reported no effect on nasal folding, whereas those that had the thermage treatment indicated a positive effect [23] . In this study, the patients who underwent thermage treatment had less nasolabial fold filler treatment. This result could be interpreted to the effect that the patients who received the thermage treatment rejected the filler treatment because it involves the invasive insertion of foreign material into the skin. A nasolabial crease is common in thin skin, and an analysis should be carried out of whether the nasolabial fold filler procedure has less of an effect on the improvement of the nasolabial crease than the thermage treatment does.

Signs of aging in the lower face are manifested as a poor definition of the mandibular margin as the facial soft tissue shifts downward due to gravity. The PDO short suture thread treatment creates a skin meshwork over the marionette line and the SMAS plane to improve the skin-tightening and rejuvenation of the lower facial area including the jawline. The Silhouette Soft Thread treatment improved the marionette line and the jawline by using the long suture technique to trap the exit point toward the insert point and the marionette line from the hairline side [24] . In a clinical study, patients who had received a minimally-invasive cosmetic procedure for their sagging jowl reported no effect; in contrast, they reported that thermage treatment was successful for this problem. These same patients, in general, had good-quality skin despite early aging, and expressed that persons who do not want an operative procedure might be satisfied with thermage tissue tightening [23] . The present study found that patients who had received thermage treatment had received fewer treatments with thread lift (P < 0.001). This result can be interpreted as reflecting the tendency of patients to receive thermage treatment instead of a relatively invasive treatment.

The limitation of this study is that causal relationships between variables cannot be identified because of the particular characteristics of the retrospective study and because there was no time series analysis on the different procedures. Future studies should analyze whether the noninvasive RF treatment improves the “skin-to-time relationship” in relation to other treatments, and, due to its superior skin improvement capability, whether it reduces the need for treatments involving botulinum toxin, filler, or thread lift. Nonetheless, this study is important since it supports the recent facial anti-aging trend in which facial treatments have moved from invasive to minimally invasive and noninvasive.

This study provides evidence that patients who undergo noninvasive RF treatment are less inclined to use botulinum toxin, filler, and thread lift procedures. These results suggest that noninvasive RF treatment is increasingly being selected by patients because of their increased rejection of invasive treatments based on their perception that they can be painful and produce side effects, especially the common botulinum toxin, filler, and thread lift procedures.

The authors declare no conflicts of interest regarding the publication of this paper.

Kim, S. and Kim, M. (2019) Trends of Noninvasive Radiofrequency and Minimally Invasive Treatment for the Management of Facial Aging. Journal of Cosmetics, Dermatological Scien- ces and Applications, 9, 30-40. https://doi.org/10.4236/jcdsa.2019.91003