Non-Traditional and Non-Invasive Approaches in Facial Rejuvenation: A Brief Review

While injectables, lasers, and surgical interventions have traditionally been used to reverse the changes associated with facial aging, other alternative therapies such as facial acupuncture and facial exercises are now being studied for facial rejuvenation. In this paper, we both summarize the concepts of facial acupuncture and facial exercises, and review seven studies that evaluate the efficacy of these modalities. Data from these studies suggest that both facial acupuncture and facial exercises have the potential to improve the skin laxity, wrinkle length, muscle thickness, and pigmentary changes associated with aging. Patients frequently reported improvement and experienced very few side effects. However, further research is necessary before these modalities are widely accepted as effective by the medical community, though the results of these studies may ultimately make providers less hesitant when patients seek out these services.


Introduction
As per a recent survey performed by the American Society of Dermatologic Surgery in 2019, nearly 70% of patients reported considering a cosmetic procedure, which is an increase from just 50% of patients in 2015 [1]. Of those participating in the 2019 survey, 70% of patients report seeking cosmetic procedures to either improve skin discoloration and texture, or lines and wrinkles around the eyes [1]. These changes are primarily a result of chronic sun exposure, though other factors such as subcutaneous fat loss and environmental exposures are said to contribute [2][3][4]. Ultraviolet light directly damages collagen and elastic fibers, which in turn leads to increased skin laxity and the formation of rhytides such as nasolabial folds and marionette lines [2][3][4]. Pigmentary changes are also associated with cumulative ultraviolet light exposure, leading to the formation of solar lentigines, telangiectases, and overall dyschromia [2]. The redistribution of subcutaneous fat in the face overtime further accentuates these changes [2].
Several invasive and minimally invasive modalities are available for reversing the above changes associated with facial aging. Invasive methods used for facial rejuvenation most often include aesthetic plastic surgery, which serves to create the outward appearance of youth but does little to address or prevent the underlying causes of facial aging [5,6]. In contrast, noninvasive approaches may be sought as either complementary to, or an alternative to, invasive methods of facial rejuvenation. Some noninvasive approaches frequently described in the literature include botulinum toxin to improve the appearance of rhytides, dermal fillers, and laser resurfacing. However, other non-traditional, noninvasive approaches, such as facial acupuncture and facial exercises, are also used despite the lack of robust research or randomized controlled trials on these modalities.
The principles of acupuncture were first developed by monks in ancient China and later became known as Qi (pronounced "chee"), which is the energy responsible for all movement and transformation in the universe [6][7][8]. Qi is divided into two parts, yin and yang. Acupuncture needles are inserted into the yin and yang channels to restore the internal balance of yin and yang through either toning or relaxing certain target areas [6,7]. Increased skin laxity, for example, would be targeted by inserting needles along a channel for toning. Several theories exist as to how acupuncture works. The endorphin model proposes that acupuncture needles inserted into specific points stimulate the production of endogenous opioids, and pre-treatment with naloxone decreases the overall pain-alleviating effects of acupuncture [8,9]. Other theories suggest that the increased electrical conductivity of tissue at the acupuncture sites results in increased circulation to the area [6,8].
Facial exercises involve a variety of strengthening movements and manipulations of facial muscles for rejuvenation. This non-invasive approach aims to strengthen facial muscle tone, thereby reducing sagging skin of the face [10]. It has been proposed that facial exercising aids in tissue regeneration by increasing circulation to the facial muscles and allowing for drainage of generated waste products [11]. The goal of facial exercising is to combat the multitude of underlying processes that cause wrinkling and skin laxity, including hormone level changes, muscle atrophy, and redistribution of subcutaneous fat [12].
Considering the growing number of patients seeking cosmetic procedures, we intend to provide a brief review of recent literature concerning the effectiveness, advantages, and disadvantages of facial acupuncture and facial exercises for facial rejuvenation.

Materials and Methods
A literature search was conducted using PubMed, Science Direct, and ClinicalKey without placing date restrictions. The following keywords were utilized: "photoaging," "facial aging," "acupuncture and facial rejuvenation," and "facial exercises." An additional search using a University library and Google Scholar was completed to be fully inclusive of pertinent research studies. Studies were considered eligible for this review based on the following inclusion criteria: (1) use of experimental design; (2) performance of facial acupuncture with quantitatively measured results; (3) performance of facial exercises with quantitatively measured results; (4) were English language literature published in a peer-reviewed journal; and (5) seminal research carried out within the last 10 years. Meta-analyses and review papers were excluded from our search. Two independent reviewers (T.F. and A.M.S) completed the previous methods separately and subsequently crossreferenced searches to further assure that no pertinent studies had been excluded from the search. Any disagreements between the two reviewers were discussed and resolved.
The papers retrieved were then combined and duplicates were excluded. A preliminary assessment of the titles and abstracts of each paper was performed, and those deemed not eligible based on the aforementioned inclusion criteria were excluded. The remaining articles underwent a full-text review with special attention also paid to the reference lists of these articles for additional relevant studies.
Collectively, 46 studies were identified through the electronic search. After removing duplicates and irrelevant studies, 29 studies remained. From the remaining studies, application of exclusion and inclusion criteria yielded a total of eight studies which were submitted to a full-text review. Table 1 details the pertinent findings from each article and is arranged by modality. Table 2 describes the advantages and disadvantages of each modality as described in the articles. Approval was obtained by the Galway Regional Hospitals major muscle thickness increased 18.7% from the baseline.
The difference in muscle thickness between NMES and control groups after 12 weeks was statistically significant (p < 0.001).

Research Ethics
Committee.

Modality Advantages Disadvantages and Adverse Events
Facial acupuncture Increase in skin oil content [13] Performed by hand, so can be used more readily on sensitive or narrow areas not amenable to certain instruments [15] Decrease in size of nasolabial folds and eye wrinkles [15] Decrease in overall melasma area and pigment darkness [16] Bruising, edema, pain at needle site [14] Foreign body granuloma [18,19] Atypical mycobacterium infection [20,21] Facial exercises Decrease in self-reported severity of wrinkles and jawline sagging [11] Potential to cause dynamic rhytides [10] Increase in muscle thickness and cross-sectional area [11,12] Increase in physician-rated upper and lower cheek fullness [17] No other adverse events reported in the literature

Results and Discussion
A total of eight studies were reviewed, four of which involved facial acupuncture and four involving facial exercises [10][11][12][13][14][15][16][17]. The countries represented in the studies involving acupuncture include Korea (n = 2), Thailand (n = 1), and Japan (n = 1). The countries represented in the studies involving facial exercises include the United States (n = 1), Belgium (n = 1), Ireland (n = 1), and Korea (n = 1). The mean age of participants receiving facial acupuncture was 46.8, whereas the mean age of participants performing facial exercises was 46.1. The majority of facial acupuncture studies included female patients only, with the exception being the study by Cho et al., which did not specify the age or gender of each participant, but did report data from male subjects [15]. All four of the facial exercise studies included female participants only. Seven of the studies took ethical considerations into account, but the remaining study by Cho et al. on facial acupuncture did not explicitly mention the process of ethics approval or written informed consent by patients [15].
Of the four studies reviewed on facial acupuncture, only one study assessed the patients' perception of improved skin elasticity. None of the patients in this study attributed the intervention of facial cosmetic acupuncture to improving their skin elasticity [14]. However, objective measurement using Moire topography criteria showed a statistically significant change in topography (p < 0.0001), with 55% of patients showing single-level improvement [14]. Each of the three remaining studies had different primary endpoints. In the study performed by Rerksuppaphol et al., the melasma pigment shading scale decreased by 3.1 units (p = 0.002), for patients receiving facial acupuncture only. Additionally, both the facial acupuncture only and the facial plus body acupuncture groups experienced a mean area reduction of 2.4 cm 2 and 2.6 cm 2 respectively (p < 0.001) [16]. The only study to measure the length of rhytides before and after acupuncture was performed by Cho et al. and showed a statistically significant decrease in the length of the left and right nasolabial folds and eye wrinkles for all age ranges included in the study [15]. The remaining study was a case series performed by Donoyama et al. to assess changes in water and oil content after five consecutive acupuncture treatments [13]. While water content for both the 50-year-old patient (A) and 29-year-old patient (B) was essentially unchanged, the oil content for patient A increased from 32% to 38%, and the oil content for patient B increased from 8% to 19% [13]. No statistical analysis was performed in this study. Given that each study looking at facial acupuncture had a slightly different patient population and primary endpoint, a unifying statement, regarding the results for facial acupuncture as it relates to facial rejuvenation, is difficult to make.
In the studies looking at facial exercises for facial rejuvenation, two of the four studies reviewed were completed using devices. One study utilized the Pao device which was made in Japan and is held in the mouth while nodding the head to train the muscles around the mouth [11]. The other study incorporated a neuromuscular electrical stimulation device that works by delivering an electric current to the muscle and thus causing repetitive muscle contraction [12]. Of the studies that used assist devices, quantitative measurements showed improved thickness and cross-sectional area of the muscles in the face. Additionally, patients' perceptions of their wrinkle severity, tone, firmness, radiance, and complexion improved following intervention with device-assisted facial muscle exercises [11,12]. The remaining studies did not use an exercise device, but rather provided patients with a therapy session to learn facial muscle exercises. In the study performed by De Vos et al., four isometric exercises were performed daily for seven weeks to target the frontalis, orbicularis oris, zygomatic minor, masseter, sternocleidomastoid, and the mylohyoid muscles [10]. The qualitative results from this study were less generalizable, as both external and self-evaluation of photographic results showed statistically significant improvement, in the upper lip and jawline only [10]. The remaining study by Alam et al., assessment by two blinded physicians using the Merz-Carruthers Facial Aging Photoscale (MCFAP), showed a statistically significant increase in upper (p = 0.003) and lower cheek (p = 0.003) fullness after completion of a 20-week facial exercise program, when compared to the baseline [17]. Overall, the data from these studies show the subjective improvement of facial aging changes which, when measured quantitatively, are complemented by increased muscle thickness.
Based on the studies that were analyzed, the quantitative results suggest that both facial acupuncture and facial exercises have the potential to affect facial aging. Additionally, patients and physician evaluators most often reported improvement in facial appearance or no change, rather than reporting worsening of their appearance. No adverse effects were reported in the facial exercise studies, and the facial acupuncture studies reported only minor bruising and pain. Furthermore, these modalities are inexpensive and offer a more cost-effective option for patients seeking facial rejuvenation. Facial exercises are a self-help approach and can be done at home, without the necessity of involving anyone else, and not requiring any cost. With regards to the implementation of these methods in their medical practice, most physicians would require further education and training on these topics. However, these results might ultimately make physicians less hesitant to refer patients to providers who offer these services.
More robust research should be conducted using facial exercises and acupuncture, particularly using larger sample sizes and within various age groups. The average sample size was N = 45, with a range of N = 2 to N = 107. The small sample sizes included in these studies prevent the generalizability of any statistically significant findings. Incorporating patients > 60 years of age would help to solidify the usefulness of both modalities in reversing the changes associated with facial aging. The addition of patients < 30 years of age would also be beneficial for determining the role of these modalities in the prevention of facial aging. More male participants should be included in future studies, as they too seek out prevention and reversal of facial aging changes. Several of the studies also included used non-randomized control designs, which may have resulted in treatment bias, and emphasizes the need for randomized controlled trial designs in future studies. It is also difficult to reach definitive conclusions using the current literature, given that each study uses different assessment scales and measurements. Further studies should, therefore, try to incorporate standardized measurement to strengthen conclusions being made from these studies and making the meta-analysis of data feasible.

Limitations
This review is associated with some limitations. The studies included were written in English language only and found only in peer-reviewed journal publications that were electronically available. There were several other studies written in Korean, Chinese, and Japanese literature that were found during the process of searching for publications that could not be used, which is a limitation of this review. Article selection of this nature leads to an unknown degree of publication bias. Furthermore, many of the experiments involved subjects' responses. Given that the improvement of facial appearance was a primary endpoint and known to participants, the use of such qualitative measures may have led to recall bias. Additionally, these studies likely attracted a specific population more willing to seek out various methods for facial rejuvenation.
For the studies included, the tools and assessments lack reliability and consistency, which constrains the external validity of the data from these studies. If consistent exercise tools were implemented vastly among people, this would allow for more validity and opportunity to assess the benefits of these exercises and tools on facial rejuvenation. Another limitation of this review is the lack of control groups in the studies included. None of the trials involving facial acupuncture had a control group, and only one of the facial exercise studies by Kavanagh et al. had a control group [12]. Given the lack of controlled trials available for these modalities, it is important to exercise caution in interpreting their effectiveness. This echoes the reality that this review is brief and not a scoping, systematic review. Definitive claims about the effectiveness of either facial acupuncture or facial exercises in treating facial aging cannot be substantiated based on the data presented in this review.

Conclusions
In recent years, alternative therapies have been developed to use in addition to or exclusive of traditional injectables, lasers, and surgical interventions for facial rejuvenation. Of these alternative therapies, facial acupuncture and facial exercises have been most studied, though research is still lacking to be sure of their efficacy. In this review, we included the results of four studies that independently evaluated facial acupuncture for decreasing the length of rhytides, improving skin laxity, and reversing the pigmentary changes associated with aging [13][14][15][16]. While statistically significant decreases in the length of nasolabial and mesolabial folds were observed in one study and were desirable outcomes, no other studies to date have used this primary endpoint [15]. The appearance and size of facial melasma after acupuncture also decreased, which might be useful for physicians taking care of patients who are refractory to traditional chemical peels, hydroquinone, retinols, or kojic acid [16]. If patients are seeking even less invasive and less expensive treatments to address the volume changes associated with facial aging, facial exercises might be beneficial. Favorable and statistically significant volume changes around the upper lip, jawline, and cheeks were observed using repeatable isometric exercises, even without the use of a device [10,17]. With some additional cost, a facial exercise device may be helpful in the subjective improvement of wrinkle severity, tone, and complexion [11,12]. However, we believe that further research is needed before these modalities become more broadly accepted by medical professionals.