A Phase-III Noninferiority, Randomized Controlled Trial of Letibotulinum Toxin A for the Improvement of Moderate-to-Severe Glabellar Wrinkles in China.

Background: Letibotulinum toxin A has an established efficacy and safety profile for aesthetic treatment of glabellar wrinkles. This study was conducted to demonstrate the noninferiority of letibotulinum toxin A versus onabotulinum toxin A in improving the appearance of moderate-to-severe glabellar wrinkles in Chinese patients. Methods: This phase-III multicenter, randomized, parallel positive control, double-blinded study compared the efficacy and safety of letibotulinum toxin A and onabotulinum toxin A. Eligible participants were randomized 3:1 to receive 20 U of letibotulinum toxin A or onabotulinum toxin A and were observed for 16 weeks postinjection. The primary endpoint was noninferiority in the proportion of study participants receiving a score of 0 or 1 for glabellar wrinkles on a four-point photographic evaluation scale, as assessed by an institution evaluator at maximum frown at week 4. Secondary endpoints included assessments at rest, photographic assessment of efficacy, and subjective self-assessment of the study participants. Results: The proportion of participants (N = 500) receiving a score of 0 or 1 at maximum frown by the institution evaluator at week 4 was 88.49% for letibotulinum toxin A and 87.39% for onabotulinum toxin A (difference, 1.10%; 95% confidence interval, -5.02 to 8.82; P = 0.7469). No significant differences were observed between the treatments for secondary efficacy or safety endpoints. Participants' self-assessment and satisfaction tended to be higher for letibotulinum toxin A than onabotulinum toxin A. Conclusion: Letibotulinum toxin A is noninferior to onabotulinum toxin A in improving the appearance of moderate-to-severe glabellar wrinkles in Chinese patients.

Dynamic Evaluation of Skin Displacement by the Frontalis Muscle Contraction Using Three-Dimensional Skin Displacement Vector Analysis.

PURPOSE: Understanding the muscle actions and resultant skin movement can enable more safe and effective botulinum toxin injection for the treatment of forehead wrinkles. We aimed to investigate skin displacement patterns of the forehead and adjacent skin due to frontalis muscle contraction using three-dimensional skin vector displacement analysis. MATERIALS AND METHODS: Thirty healthy individuals were enrolled. Photographs of the face were taken at rest and during maximal contraction of the frontalis muscle. Each expression image was aligned to its respective static image to compute the differences in the skin position. RESULTS: When frontalis muscle contracts, forehead skin displacement vectors were mostly vertical (63.4%), followed by lateral oblique (33.3%) and medial oblique (3.3%). In 53.3%, only the lower part of the forehead moved upward, while 40.0% showed bidirectional skin movement with transition line at a mean distance of 59.4 mm above the pupil. Moreover, 86.7% showed asymmetric skin displacement, and 83.3% showed both glabellar and eyebrow skin displacement. Frontalis muscle contraction also induced medial 2/3 (50.0%) or entire (33.3%) skin movement of the temple. CONCLUSION: Botulinum toxin injection into the forehead can be individualized by considering the vector and asymmetry of skin displacement. Vertical or medial vector requires more centrally located injections, while laterial vector requires more laterally located injections. The presence and location of the vertical transition line are important for preventing ptosis when treating forehead lines with botulinum toxin. Glabellar movement during frontalis contraction suggests the need for a concomitant injection into the glabella to prevent glabella wrinkle accentuation.

Deformation characteristics of hydrogel products based on cross-linked hyaluronic acid.

BACKGROUND: The cross-linked hyaluronic acid (HA) fillers are the viscoelastic hydrogel with a dominant elasticity rather than a viscosity as a useful medical device in the soft tissue augmentation. These HA fillers undergo deformation to begin the biodegradation by the biochemical and physical environment of the body, and result of deformations are closely related to clinical performance. AIMS: The specific equation of molding index is newly generated and proved with Collin's equation, which is used for strong elastomers, for selecting optimal product in facial treatment. METHODS: In this study, the results of amplitude sweep test from five marketed HA fillers were mathematically demonstrated for the proper clinical application. RESULTS: The increment of loss modulus by deformation was evaluated as a useful factor for the maintenance of optimal shape molding performance and resistance to external deformation of the cross-linked HA gel. From this study, the equation of molding index for weak viscoelastic hydrogels like HA products can be applied for choosing which products even in aesthetic plastic field. This molding index equation is compared to Collins' equation that index of deformation as elastomer like rubber and then found the positive correlation between two equations. CONCLUSION: This study could provide a basic theory that achieve useful clinical performance according to characteristics among many types of medical devices based on the molding index.

Use of LetibotulinumtoxinA for Aesthetic Treatment of Asians: A Consensus.

Treatment of wrinkles and dynamic lines with botulinum toxin has been a routine practice for years in aesthetic clinical settings. The effective treatment of wrinkles requires a comprehensive understanding of facial expression muscles and their interactions, the mechanism of action of botulinum toxin, and individual patient preferences. The dose adjustment practice and injection technique of physicians are affected by cultural differences; most Asian patients prefer natural-looking results. This article aims to present an expert consensus on the injection sites, doses, and levels of botulinum toxin for various indications in Asians, with the hope of providing guidance to some clinicians. This consensus paper reviews LetibotulinumtoxinA for patient evaluation, dosage, and delivery techniques in Asians from the time LetibotulinumtoxinA was approved up to December 2022. Panelists proposed individualized treatment plans for botulinum toxin type A (BTxA) treatments in 3 areas-wrinkle removal, contour adjustment, and face lifting-for Asians based on their extensive experience and knowledge of facial anatomy. When using a different BTxA, clinicians should start with a conservative dose and carefully individualize the treatment for each patient, and adjust it according to feedback to obtain a higher satisfaction level.

Pre-injection ultrasound scanning for treating temporal hollowing.

BACKGROUND: Hyaluronic acid filler injection is commonly administered to correct temple hollowness, typically through deep temporal injection. Since the vascular distribution at the injection site can be diverse, studies on avoiding damage to the corresponding blood vessels are needed. AIMS: To assess the commonly used hyaluronic acid filler injection site in the temple region, 1cm lateral and 1 cm above from the end of eyebrow, using a Doppler ultrasound to detect any anatomic variations in the blood vessels. PATIENTS/METHODS: Thirty patients (60 temples, right and left) were examined using Doppler ultrasonography. An 8-17 MHz ultrasound probe was used to discriminate between the anatomic layers of the temple. Blood vessels found in each anatomical layer were subsequently investigated. RESULTS: Among the 30 patients included in this study, we found temporal region arteries 1 cm above and 1 cm lateral to the distal end of the eyebrow in 9 patients; However, no arteries were detected in the temples of 21 patients. The presence or absence of arteries was bilateral in all patients. CONCLUSIONS: The anatomical layers with blood vessels varied among patients. The variability could give rise to complications. Possible anatomic variations at the temple should be carefully identified using pre-injection ultrasonography, and harming blood vessels should be avoided while injecting hyaluronic acid filler for temple augmentation.

Dynamic evaluation of facial muscles: 3D skin displacement vector analysis using a facial painting model.

BACKGROUND: Botulinum toxin A can be used to eliminate dynamic wrinkles by relaxing the muscles involved in facial expressions. Therefore, it is essential to know the location, origin, insertion, function, and changes of the facial expression muscles according to their contraction. METHODS: After drawing the muscles on the face of a model, pictures were taken at rest. The model was then asked to make facial expressions that cause facial wrinkles. All images were taken with the Vectra H1 camera system (Canfield Scientific, Inc., Fairfield, New Jersey). Each expression image was aligned to its respective static image to compute the differences in skin position, so as to calculate the skin displacement vectors. The values for local changes in skin displacement were calculated by applying the automated algorithms of the Vectra Software Mirror Suite and visualized using the color and size of the arrow. RESULTS: Face painting and 3D skin vector displacement analyses enabled visualization of all the facial muscles involved in facial expressions working dynamically, allowing us to visualize the effect of each muscle in the creation of hyperkinetic wrinkles. Face painting and 3D skin vector displacement analyses can be combined to determine the location of the wrinkles, extent of the muscle, part of the muscle that contracts, presence of asymmetry, direction in which the muscle contracts, and correlation between the antagonists and synergistic muscles. CONCLUSION: The botulinum toxin A injection educational model using body painting and 3D skin vector displacement analyses can provide a deeper understanding of actual moving muscle anatomy. LEVEL OF EVIDENCE: 4.

Proposed Treatment Protocols for Facial Rejuvenation Using a Novel Absorbable Polydioxanone Monofilament Threadlift in Koreans: Empirical Perspectives of Aesthetic Physicians and Surgeons.

BACKGROUND: Aesthetic physicians and surgeons should consider differences in anthropometric and anatomical characteristics between Asians and Caucasians in performing facial rejuvenation procedures using absorbable threadlifts in Koreans. OBJECTIVES: This paper was prepared to propose empirical treatment protocols for Korean aesthetic physicians and surgeons. METHODS: A panel of 5 Korean experts on the aesthetic uses of an absorbable polydioxanone (PDO) monofilament threadlift (Mint Lift; HansBiomed Co. Ltd., Seoul, Korea), thus termed as "the Mint Consensus Group," was convened to recommend practical guidelines for empirical treatment with the Mint Lift. RESULTS: To summarize, our recommendations are as follows: First, the entry and exit points should be determined considering the anatomical characteristics of the face (level of evidence III). Second, treatment procedures may vary depending on indications (level of evidence III). CONCLUSIONS: Here, the authors propose empirical treatment protocols for facial rejuvenation using a novel absorbable PDO monofilament threadlift in Koreans. But more evidence-based efforts should be made to update the current treatment protocols.

Aspiration Revisited: Prospective Evaluation of a Physiologically Pressurized Model With Animal Correlation and Broader Applicability to Filler Complications.

BACKGROUND: Aspiration testing before filler injection is controversial. Some believe that aspiration can help prevent inadvertent intravascular injection, whereas others cite false-negative results and question its value given that the needle position always changes somewhat during injection procedures. OBJECTIVES: The authors sought to test the relation of false-negative results to the viscosity of the material within the needle lumen and determine whether a less viscous material within the needle lumen could decrease the incidence of false-negative results. METHODS: In vitro aspiration tests were performed utilizing 30-G and 27-G needle gauges, 2 cross-linked hyaluronic acid fillers, normal saline bags pressurized at 140 and 10 mmHg to mimic human arterial and venous pressures, and 3 needle lumen conditions (normal saline, air, and filler). Testing was repeated 3 times under each study condition (72 tests in total). For in vivo correlation, aspiration tests were performed on femoral arteries and central auricular veins in 3 rabbits (4-5 aspirations per site, 48 tests in total). RESULTS: In vitro and in vivo testing utilizing 30-G needles containing filler both showed false-negative results on aspiration testing. In vitro and in vivo testing utilizing needles containing saline or air showed positive findings. CONCLUSIONS: False-negative results from aspiration testing may be reduced by pre-filling the needle lumen with saline rather than a filler. The pressurized system may help overcome challenges of animal models with intravascular pressures significantly different from those of humans. The adaptability of this system to mimic various vessel pressures may facilitate physiologically relevant studies of vascular complications.

A Safe Doppler Ultrasound-Guided Method for Nasolabial Fold Correction With Hyaluronic Acid Filler.

BACKGROUND: Injection of hyaluronic acid filler, a common procedure for nasolabial fold correction, poses a risk of vascular compromise, which can result in skin necrosis and blindness. OBJECTIVES: The aim of this study was to examine the facial arterial pathway in real time by Doppler ultrasound to avoid arterial complications during filler injections. METHODS: The facial artery pathway of 40 patients (80 nasolabial folds; 2 men and 38 women; mean age, 46.5 years; range, 28-72 years) was examined by Doppler ultrasound before hyaluronic acid filler injection. On the basis of this ultrasound evaluation, the filler injection targeted the subdermal, subcutaneous, and deep to submuscular layers by bypassing the facial artery. The efficacy of the filler injection was evaluated for each patient. RESULTS: The facial artery was detected lateral to the nasolabial fold in 31% of patients; it was detected beneath the nasolabial fold in the other patients as follows: subdermal layer, 13%; subcutaneous layer, 29%; muscular layer, 24%; and submuscular layer, 4%. The mean [standard deviation] Wrinkle Severity Rating Scale score was 3.68 [0.76] before injection and 2.28 [0.78] at 3 months after injection. Two patients experienced unilateral bruising of the nasolabial fold, which resolved after 2 weeks without treatment. CONCLUSIONS: Doppler ultrasound can be considered as pretreatment tool for the prevention of vascular complications during filler injections to correct nasolabial folds.

Doppler Ultrasonographic Anatomy of the Midline Nasal Dorsum.

BACKGROUND: This study was performed to identify a safe method for filler injection to prevent blood vessel damage, by means of checking the location and depth of the blood vessels on the midline of the nose using Doppler ultrasonographic imaging. METHODS: Ultrasonographic images of the nasal areas of patients for filler injection rhinoplasty were reviewed. The location and depth of the dorsal nasal arteries and the intercanthal vein in each part on the midline of the nose were checked. RESULTS: The intercanthal vein was detected in the midline of the radix in 22 patients and the midline of the rhinion region in two patients. There were no patients in whom the intercanthal vein was observed in the midline of the supratip region. The dorsal nasal artery was detected in the rhinion region in six patients and in the supratip region in two patients. There were no patients in whom the dorsal nasal artery was observed in the midline of the radix. The dorsal nasal artery was located within 1.2 mm from the perichondrium or periosteum in three patients in whom it was detected in the rhinion. CONCLUSIONS: When performing dorsal augmentation, the injection of filler into the preperiosteal layer in the rhinion region should be avoided for the prevention of vascular embolism. During dorsal augmentation in patients with a nasal hump, the filler can be injected into the preperiosteal space in the radix by introducing a needle perpendicular to the periosteum from the skin. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Safe Glabellar Wrinkle Correction With Soft Tissue Filler Using Doppler Ultrasound.

BACKGROUND: Glabellar wrinkle corrections are usually performed by injecting botulinum toxin and hyaluronic acid fillers. The glabella is one of the most dangerous locations for filler injection because of possible visual complications. OBJECTIVES: The aim of this study was to use Doppler ultrasound to determine the anatomic relation between glabellar wrinkles and the supratrochlear artery pathway, perform safe hyaluronic acid filler injection to correct glabellar wrinkles, and determine the efficacy of the procedure. METHODS: From January 2019 to July 2019, 42 patients (74 glabellar wrinkle lines; 32 bilateral and 10 unilateral wrinkles) were evaluated. Glabellar wrinkle lines were corrected with hyaluronic acid filler. Doppler ultrasound was used to avoid the supratrochlear artery. RESULTS: Among the 74 wrinkle lines, the supratrochlear arteries were located either at the glabellar wrinkle lines (30/74, 41%) or lateral to the glabellar wrinkle lines (44/74, 59%). In the latter 44 wrinkles, fillers were injected into the subdermal layer of the glabellar wrinkle lines. In the 30 wrinkles where supratrochlear artery was located at the glabellar wrinkle lines, the artery was located at the deep subcutaneous layer in 24 and at the subdermal layer in 6; thus, filler injection was not performed. CONCLUSIONS: The supratrochlear artery may be located either at or lateral to the glabellar wrinkle lines. When performing glabellar wrinkle correction, Doppler ultrasound can be used to confirm the location of the supratrochlear artery before filler injection, which helps in avoiding vascular complications.

Expert Consensus on Hyaluronic Acid Filler Facial Injection for Chinese Patients.

BACKGROUND: Beauty standards vary by race and region, which must be accounted for in creating beauty. Chinese have unique features, including a depressed nose, flat midface, and small chin, and have different cosmetic concerns. We performed a consensus study on filler injections based on the Chinese standard of beauty due to a lack of such study. METHODS: We organized the YVOIRE Consensus Group, including 5 plastic surgeons. We discussed common problematic areas seen in Chinese and described techniques based on our experience with hyaluronic acid fillers, while considering peer-reviewed articles, followed by multiple consensus-developing sessions. RESULTS: Chinese faces are characterized by retruded forehead, chin, and low nasal bridge, with certain features believed to bring good fortune. Therefore, profiles of the forehead, nose, lip, and chin have substantial effects on attractiveness. The demand for cosmetic procedures is high among the young generation who particularly desire nose and chin augmentation. Attractive Chinese facial shapes are characterized by a long, slender facial shape and pointed chin. Lips are narrow and thick. When injecting fillers for Chinese, it is necessary to apply special methods that produce results consistent with these characteristics. CONCLUSIONS: Understanding the concept and demand of beauty depending on race and region is important. Patients should be evaluated before aesthetic procedures. Maintaining hygiene during the procedure is crucial. Moreover, methods for preventing pain are essential. Fillers should be injected into the correct anatomical site and layer to minimize side effects and maximize effectiveness.

Short-term Treatment Outcomes of Facial Rejuvenation Using the Mint Lift Fine.

BACKGROUND: Threadlifts are classified as absorbable or nonabsorbable, natural or synthetic, and multifilament or monofilament ones, each of which has its own merits and demerits. We placed a novel absorbable polydioxanone monofilament threadlift (Mint Lift Fine; HansBiomed Co. Ltd., Seoul, Korea) in the subcutaneous fat compartment for facial rejuvenation in patients with nasolabial folds, nasojugal groove, marionette lines, or sagging jowl. Here, we describe its short-term treatment outcomes in a retrospective consecutive series of 21 patients. METHODS: A total of 21 patients (n = 21) were evaluated; their treatment outcomes were described based on a comparison between preoperative and postoperative findings and Global Aesthetic Improvement Scale (GAIS) scores were assessed at 6 months. This is accompanied by analysis of the incidence of postoperative complications. RESULTS: The patients had a mean GAIS score of 3.62 ± 0.84 points, which corresponds to "Much improved" or "Very much improved." Moreover, there were no significant differences in the GAIS scores between the target sites (midface and lower face: 3.78 ± 1.13; lower face: 3.43 ± 0.50; and midface: 3.60 ± 0.49; P > 0.05). Furthermore, there were a total of 4 cases (19.0%) of postoperative complications, all of which were spontaneously resolved within a maximum period of 4 months. CONCLUSIONS: We describe short-term treatment outcomes of facial rejuvenation using the Mint Lift Fine in patients with nasolabial folds, nasojugal groove, marionette lines, or sagging jowl. But further large-scale, prospective, multicenter studies with long periods of follow-up are, therefore, warranted to establish our results.

Doppler ultrasound-guided thread lifting.

BACKGROUND: Although there are various techniques of thread lifting, most of these techniques require anchoring of the threads at the temple area. However, the frontal branch of the superficial temporal artery (FBrSTA) is located in the temple area and a detour pathway should be created for thread insertion to avoid vascular complications. OBJECTIVES: We aimed to determine the relationship between the FBrSTA and the hairline using real-time Doppler ultrasound. METHODS: Doppler ultrasound was used to detect the FBrSTA pathway, and the relationship between the hairline and the FBrSTA was analyzed. After confirming the arterial pathway, thread lifting was performed in patients, and complications related to the entry point and insertion of the threads were evaluated. Patient satisfaction was evaluated immediately after the procedure and 3 months later. RESULTS: This study included 50 patients (45 women and 5 men; age: 51 [range 26-71] years) who underwent thread lifting in a single institution from January to May 2019 after Doppler ultrasound-guided detection of the FBrSTA. No vascular complications were noted in all patients. CONCLUSIONS: Our findings suggest that Doppler ultrasound can be used to detect the FBrSTA at the temple area to avoid vascular complications during thread lifting.

Soft Tissue Filler Properties Can Be Altered by a Small-Diameter Needle.

BACKGROUND: Small-bore needles reduce the complications associated with soft tissue filler injection. Gel particles must be sized appropriately to pass through fine-bore needles with an acceptable extrusion force. However, most soft tissue filler particles are larger than the inner diameter of the needle. The authors hypothesized that the physical properties of these particles change as the gel passes through the needle. OBJECTIVE: The authors aimed to investigate whether the predesigned physical and rheological properties of the filler change after passage through the small-bore needle. METHODS AND MATERIALS: Particle sizes of 4 hyaluronic acid (HA) fillers were analyzed using a particle size analyzer. Five soft tissue fillers with different particle sizes were subjected to rheological characterization. All tests were performed using fillers with and without a 30-G needle. RESULTS: Monophasic HA fillers with smaller particle sizes exhibited small changes between particle sizes but no differences in rheological properties. Biphasic HA fillers with larger particle sizes exhibited remarkable changes in particle size and rheological properties. Calcium fillers exhibited changes in rheological properties. CONCLUSION: Injection through small-bore needles can alter the physical properties and rheological equilibrium of soft tissue fillers. The authors suggest avoiding small-bore needles as they may affect the rheological equilibrium and clinical performance of fillers.

Injection Rhinoplasty Using Filler.

Rhinoplasty is a commonly performed cosmetic surgery in Asia. Rhinoplasty using filler is preferred because has fewer side effects and shorter down time. The part of external nose between the skin and bone or cartilages consists of 4 layers. To prevent vascular compromise, the injection should be into deep fatty layer, preventing embolization. Filler is usually injected in the order of radix, rhinion, tip, and the supratip area. To minimize asymmetry, the surgeon should always mark the midline on the nasal bridge and perform the procedure without deviating from it.

Multi-polydioxanone (PDO) scaffold for forehead wrinkle correction: A pilot study.

BACKGROUND: Forehead wrinkles are the result of contracture of the frontalis muscle and the skin aging process. Currently, hyaluronic acid filler and botulinum toxin are the main materials used for correction of these wrinkles. In addition, polydioxanone (PDO) thread has also been applied for this treatment. OBJECTIVE: In order to evaluate the efficacy and safety of multi-PDO scaffold in animal and human skin, we tested PDO insertion in rat and mini-pig models and human volunteers with forehead wrinkles. METHODS: A stent-shaped multi-PDO scaffold was inserted under the panniculus carnosus of rat dorsal skin and the subcutaneous layer of mini-pig dorsal skin and forehead wrinkles in three human volunteers. RESULTS: Histological analysis at 12 weeks revealed evidence of de novo collagen synthesis, which was consistent with clinical results on photo evaluation. CONCLUSION: Stent-shaped multi-PDO scaffolds may be another effective and safe treatment modality for reduction of forehead wrinkles.