"Efficacy and Safety of OnabotulinumtoxinA for the Treatment of Platysma Prominence: A Randomized Phase 2 Dose-Ranging Study".

BACKGROUND: With aging, repetitive contraction of the platysma leads to an increase in platysma prominence (PP) characterized by the accentuation of vertical neck bands and blunting of the jawline's contour. METHODS: This multicenter, double-blind, phase 2 study evaluated onabotulinumtoxinA (onabotA) treatment in adults with Moderate to Severe PP. Participants were randomized to receive 1 treatment of onabotA low dose (LD), onabotA high dose (HD), or placebo, and were followed for 4 months. Efficacy endpoints were the achievement of a ≥ 1-grade improvement on both the left and right sides at Day 14 at maximum contraction as assessed by the investigator (primary) or by participants (secondary) using validated scales. Safety was evaluated throughout. RESULTS: Participants in the modified intent-to-treat population (N = 164) had a mean age of 50 years; 95.1% were female and 93.9% were White. The primary endpoint was met for both onabotA groups, with investigator-assessed ≥ 1-grade improvement in 77.8% (LD) and 88.2% (HD) vs 12.0% (placebo) of participants on Day 14 (P < 0.0001 vs placebo). Based on participant self-assessment, 75.9% (LD) and 88.2% (HD) vs 18.0% (placebo) achieved ≥ 1-grade improvement on Day 14 (P < 0.0001 vs placebo). Most treatment-related adverse events (AEs) were procedure-related, transient, and mild in severity. The most frequent onabotA-related AE was neck muscle weakness, reported in the HD group. CONCLUSIONS: OnabotA was effective in improving the appearance of PP based on both investigators' and participants' ratings. Treatment was well tolerated.

Effectiveness and Safety of a New Hyaluronic Acid Injectable for Augmentation and Correction of Chin Retrusion.

BACKGROUND: A hyaluronic acid (HA) filler intended for non-surgical improvement of chin appearance should ideally be of high strength/firmness (high G') to allow for deep injections on the bone. HASHA (Restylane Shaype) is a new hyaluronic acid (HA) injectable with high G' and high HA concentration (25 mg/mL), engineered by the new NASHA-HD (High Definition) technology. HASHA is suitable to be placed periosteally, aiming to mimic the natural shape of the bony chin. This pivotal clinical investigation evaluated effectiveness and safety of HASHA for augmentation and correction of chin retrusion.  Methods: Subjects 18 years or older with mild or moderate chin retrusion by the Galderma Chin Retrusion Scale (GCRS), were randomized 3:1 to HASHA (n=103) or no treatment (n=37). Assessments included GCRS (blinded evaluator), aesthetic improvement (Global Aesthetic Improvement Scale [GAIS]), subject satisfaction, and safety.  Results: GCRS responder rate (1-grade or greater improvement from baseline) was significantly higher for HASHA (83.3%) versus controls (10.8%) at month 3 (P<0.001) and maintained through month 12 (P<0.001). Aesthetic improvement was high throughout the study in the HASHA group, according to investigators (97% or greater) and subjects (89% or greater). Overall, subject satisfaction was high at month 3 and maintained at month 12. Product- or injection-related adverse events were mostly mild or moderate and transient. No product- or injection-related serious adverse events were reported. CONCLUSIONS: HASHA, a new NASHA-HD injectable with extra strength/firmness, was safe and effective for chin augmentation and correction of chin retrusion, with high aesthetic improvement and subject satisfaction throughout 12 months. J Drugs Dermatol. 2024;23(4):255-261.     doi:10.36849/JDD.8145.

Applicability of Patient-Reported Outcome Measures to Aesthetic Medicine Patient Archetypes.

BACKGROUND: Patient-reported outcome measures (PROMs) are valuable in understanding patient motivations, setting expectations, and ensuring satisfaction. As the aesthetic industry expands globally, factors that motivate the treatment goals of the aesthetic patient reflect evolving social, cultural, and commercial influences. OBJECTIVE: This article will assess the applicability of current PROMs used in aesthetic medicine to an increasingly diverse patient population and consider their ability to measure the underlying motives that drive different types of patients to pursue their specific goals. METHODS: PubMed database was searched for studies using PROMs to evaluate the motivations and expectations of aesthetic patients. RESULTS: Seven validated aesthetic PROM tools were reviewed against a backdrop of different patient segments as represented by the 4 patient archetypes: Positive Aging, Beautification, Correction, and Transformation. None of the tools could universally represent the individual motivations and expectations of all 4 patient archetypes. CONCLUSION: There is a need for updated PROMs in aesthetics that are applicable to patients with different motivations or expected outcomes than the traditional rejuvenation patient. PROMs that help decode patient motivations and that are developed with more diverse patient involvement will help aesthetic clinicians better understand the goals and expectations of new patient segments.

Intralabial Lip Compartments and their Potential Clinical Relevance.

BACKGROUND: Aesthetic soft tissue filler injections for lip enhancement are highly popular and are performed throughout the world. When injecting lips with cannulas, as the cannula is advanced, resistance is perceived in consistent locations potentially indicating boundaries between intralabial compartments. OBJECTIVE: To investigate whether intra-labial compartments exist and (if so) to describe their volumes, location, boundaries, and dimensions. METHODS: This cadaveric study investigated a total of n = 20 (13 males, 7 females) human body donors with a mean age at death of 61.9 (23.9) years and a mean body mass index of 24.3 (3.7) kg/m 2. The investigated cohort included n = 11 Caucasian, n = 8 Asian, and n = 1 African American donors. Dye injections simulating minimally invasive lip treatments were conducted. RESULTS: Independent of gender or race, 6 anterior and 6 posterior compartments in the upper and lower lip were identified, for a total of 24 lip compartments. Compartment boundaries were formed by vertically oriented septations that were found in consistent locations. The anterior compartments had volumes ranging from 0.30 - 0.39 cc whereas the posterior compartment volume ranged from 0.44 - 0.52 cc. Centrally, the compartment volumes were larger and decreased gradually towards the oral commissure. CONCLUSION: The volume and the size of each of the 24 compartments contribute to the overall appearance and shape of the lips. To achieve a natural and lip-shape preserving aesthetic outcome it may be preferable to administer the volumizing product using a compartment-respecting injection approach.

Assessment and Treatment Strategies for the Aesthetic Improvement of the Lower Face and Neck.

Background: Interest in aesthetic rejuvenation of the lower face and neck is growing, but published expert guidance is limited. Objective: Review aesthetic concerns of the lower face and neck and provide expert guidance on evaluation and treatment. Methods: Twelve international experts participated in an advisory board on lower face and neck aesthetic treatment. They completed a premeeting survey and met twice, reviewing responses and discussing patient evaluation and treatment strategies. They developed decision tree algorithms on patient assessment and treatment planning and sequencing, using clinical cases as a reference. Results: Treatment concerns include neck and lower face skin laxity, structural bone deficiency, insufficient or excess volume, submental fat, jowls, platysma bands, and masseter muscle prominence. Advisors agreed that the lower face and neck may be the most challenging areas to assess and treat; treatment goals include lower facial contour and overall facial harmony/balance. Advisors recommended first ruling out a surgical approach, then determining whether midface treatment is needed to support the lower face, and lastly evaluating the lower face for significant submental fat, excess or insufficient volume, and structural bone deficiency. To treat the lower face and neck, an anatomical layer approach, moving from deep to superficial layers, beginning with structural support, was recommended. Assessment and treatment decision trees were based on this approach. Conclusion: The lower face and neck are important but underrecognized areas of aesthetic concern. This article provides expert guidance and a suggested algorithm for assessment and treatment aimed at achieving satisfying and harmonious facial aesthetic results.

Integrative Assessment for Optimizing Aesthetic Outcomes When Treating Glabellar Lines With Botulinum Toxin Type A: An Appreciation of the Role of the Frontalis.

Despite the perception that treatment of glabellar lines with botulinum toxin A is straightforward, the reality is that the glabellar region contains a number of interrelated muscles. To avoid adverse outcomes, practitioners need to appreciate how treatment of 1 facial muscle group influences the relative dominance of others. In particular, practitioners need to understand the independent role of the frontalis in eyebrow outcomes and the potential for negative outcomes if the lower frontalis is unintentionally weakened by botulinum toxin A treatment. In addition, practitioners must recognize how inter-individual variation in the depth, shape, and muscle fiber orientation among the upper facial muscles can affect outcomes. For optimal results, treatment of the glabellar complex requires a systematic and individualized approach based on anatomical principles of opposing muscle actions rather than a one-size-fits-all approach. This review provides the anatomical justification for the importance of an integrated assessment of the upper facial muscles and eyebrow position prior to glabellar treatment. In addition, a systematic and broad evaluation system is provided that can be employed by practitioners to more comprehensively assess the glabellar region in order to optimize outcomes and avoid negatively impacting resting brow position and dynamic brow movement.

Impact of Glabellar Injection Technique With DaxibotulinumtoxinA for Injection on Brow Position.

BACKGROUND: Precise injection technique is vital for avoiding suboptimal eyebrow position when treating glabellar lines with botulinum toxin type A. OBJECTIVES: The aim of this study was to evaluate the impact of glabellar injection technique on eyebrow position in patients treated with DaxibotulinumtoxinA for Injection (DAXI). METHODS: This retrospective post hoc analysis involved 60 adults who received a single treatment with DAXI 40 U to the glabella and had standardized facial photography. Median vertical and horizontal displacement of the brows (at rest) at baseline and 2 weeks after glabellar injection were measured. Brow position outcomes were evaluated by an oculoplastic surgeon and expert anatomist. Investigators were interviewed to ascertain individual injection techniques. RESULTS: Precise injection location and depth, and median resting brow position following treatment varied between investigators. Positive brow outcomes were achieved with deep DAXI injections into the medial corrugator, superficial lateral corrugator injections placed between the midpupil and lateral limbus, and deep midline procerus injections. Glabellar injection technique that more precisely targeted the corrugator muscles resulted in longer glabellar line treatment duration compared to a less targeted technique. Medial corrugator injections above the medial brow; lateral corrugator injections administered deeply or more medially, toward the medial third of the brow; and procerus injections superior to the inferomedial brow tended to be associated with suboptimal outcomes that were more apparent during dynamic expression. CONCLUSIONS: Aesthetically pleasing brow outcomes and greater duration of efficacy can be achieved with an injection pattern that precisely treats the anatomic location of the corrugator supercilii and procerus muscles, avoiding the frontalis.

PrabotulinumtoxinA vs OnabotulinumtoxinA for the Treatment of Adult Males With Moderate to Severe Glabellar Lines: Post-hoc Analyses of the Phase III Clinical Study Data.

BACKGROUND: Despite a growing interest among men in cosmetic procedures such as botulinum toxin, comparator clinical trial data in this population are limited. OBJECTIVES: The authors sought to compare the efficacy and safety of prabotulinumtoxinA and onabotulinumtoxinA for the treatment of males with moderate to severe glabellar lines. METHODS: Post-hoc analyses were performed on the subpopulation of male patients treated with either a single dose of 20 U prabotulinumtoxinA (n = 25) or 20 U onabotulinumtoxinA (n = 31) in the EVB-003 Phase III glabellar line clinical study. One key efficacy endpoint was the proportion of responders with a ≥1-point improvement from baseline at maximum frown on the 4-point Glabellar Line Scale. RESULTS: Compared with onabotulinumtoxinA-treated males, the percentages of responders who had a ≥1-point improvement on the Glabellar Line Scale at maximum frown were higher at all postbaseline time points for prabotulinumtoxinA-treated males (P > 0.05 at all visits) by an absolute overall mean difference of 10.1% across all visits. Similar trends were observed for efficacy endpoints based on global aesthetic improvement and subject satisfaction. PrabotulinumtoxinA-treated males had a higher incidence of treatment-related headache and eyelid ptosis. CONCLUSIONS: The percentages of patients who met the definition of a responder were higher at almost all time points examined for prabotulinumtoxinA-treated males. Despite the high level of consistency across all measures, differences between the 2 treatment groups did not reach statistical significance. Further study is warranted to establish if these post-hoc analyses observations are reproducible in a larger male patient population.

The Anatomy behind Eyebrow Positioning: A Clinical Guide Based on Current Anatomic Concepts.

BACKGROUND: The position of the eyebrow is known to reflect emotional status and to provide a plethora of nonverbal information. Although the eyebrow has no direct attachment to underlying bone, it is subject to the interplay between the various periorbital muscles, which when acting together, permit important nonverbal cues to be conveyed. Understanding the balance and interplay between these muscles is of crucial importance when targeting the periorbital area with neuromodulators. The authors' aims were to summarize current anatomic and clinical knowledge so as to provide a foundation that physicians can rely on to improve and increase the predictability of patient outcomes when treating the periorbital region with neuromodulators for aesthetic purposes. METHODS: This narrative review is based on the anatomic and clinical experience of the authors dissecting and treating the periorbital region with specific focus on the glabella and the forehead. RESULTS: This narrative review covers (1) a brief description of the relevant periorbital muscle anatomy, (2) an analysis of each muscle's contribution to various facial expressions, and (3) an anatomic and physiologic simulation of the muscular effects of specific neuromodulator injection sites. CONCLUSION: By understanding functional anatomy of the periorbital muscles and combining this knowledge with individualized assessment and treatment planning, it is possible to achieve aesthetically pleasing, predictable, and reproducible treatment outcomes that positively impact perception of nonverbal cues when administering neuromodulators.

Role of botulinum toxin A in improving facial erythema and skin quality.

Botulinum toxin A (BTX-A) injections have become the most popular noninvasive cosmetic procedures performed worldwide. With growing interest, investigators continue to uncover an expanding array of aesthetic indications for BTX-A. Botulinum toxin A has been used off-label in the management of masseter hypertrophy for facial slimming, platysmal bands, nasal 'bunny' lines, perioral rhytides, gummy smile and scars, to name a few. Interestingly, the injection of multiple microdroplets of dilute BTX-A into the dermis, sometimes referred to as 'microbotox', has been investigated as a tool for facial rejuvenation. A handful of prospective studies and case series have demonstrated the benefit of BTX-A in the treatment of facial erythema and improving skin texture. The aim of this review is to summarize and appraise currently available data on the role of BTX-A in treating facial erythema and skin quality, with a special focus on potential pathophysiologic mechanisms.

Change in Rheologic Properties of Facial Soft-Tissue Fillers across the Physiologic Angular Frequency Spectrum.

BACKGROUND: The number of soft-tissue filler injections performed in the United States is constantly increasing and reflects the high demand for enhanced facial and body attractiveness. The objective of the present study was to measure the viscoelastic properties of soft-tissue fillers when subjected to different testing frequencies. The range of tested frequencies represents clinically different facial areas with more [lips (high frequency)] or less [zygomatic arch (low frequency)] soft-tissue movement. METHODS: A total of 35 randomly selected hyaluronic acid-based dermal filler products were tested in an independent laboratory for their values of G', G″, tan δ, and G* at angular frequencies between 0.1 and 100 radian/second. RESULTS: The results of the objective analyses revealed that the viscoelastic properties of all tested products changed between 0.1 and 100 radian/second angular frequency. Changes in G' ranged from 48.5 to 3116 percent, representing an increase in their initial elastic modulus, whereas changes in G″ ranged from -53.3 percent (i.e., decrease in G″) to 7741 percent (i.e., increase in G″), indicating both an increase and a decrease in their fluidity, respectively. CONCLUSIONS: The increase in G' would indicate the transition from a "softer" to a "harder" filler, and the observed decrease in G″ would indicate an increase in the filler's "fluidity." Changes in the frequency of applied shear forces such as those occurring in the medial versus the lateral face will influence the aesthetic outcome of soft-tissue filler injections.

Efficacy and Safety of Flexible Hyaluronic Acid Fillers in Lip and Perioral Enhancement.

BACKGROUND: Since lips have a significant role in facial aesthetic perception, lip augmentation is an increasingly popular aesthetic procedure. OBJECTIVE: To evaluate aesthetic improvement and facial dynamics with hyaluronic acid (HA) fillers in the lips and perioral region at 8 weeks after the last treatment compared to pre-treatment. METHODS AND MATERIALS: In this open-label study, all subjects received HARK in the lips, and an additional group also received HARR and/or HARD in nasolabial folds (NLFs) and marionette lines (MLs). Assessments included aesthetic improvement, naturalness of facial expressions, perception of age, and lip texture. RESULTS: Nineteen subjects received HARK only; 40 received HARK and HARR and/or HARD. The primary objective was met. All subjects experienced aesthetic improvement in lip fullness at week 8. The investigators also reported aesthetic improvement in all subjects. For the majority of subjects, aesthetic improvement was associated with maintenance of natural and youthful facial expressions, and improved lip texture. Most treatment-emergent adverse events were mild; none were serious. CONCLUSION: HARK is a well-tolerated and effective treatment for enhancing lip fullness, maintaining naturalness and youthfulness of facial expressions, and smoothing lip texture, whether used alone or in combination with HARR/ HARD in the NLFs and/or MLs. J Drugs Dermatol. 20(4): 402-408. doi:10.36849/JDD.2021.5525.

The Change of Plane of the Supratrochlear and Supraorbital Arteries in the Forehead-An Ultrasound-Based Investigation.

BACKGROUND: Injecting soft tissue fillers into the deep plane of the forehead carries the risk of injection-related visual compromise due to the specific course of the arterial vasculature. OBJECTIVES: The aim of this study was to investigate the 2- and 3-dimensional location of the change of plane of the deep branch of the supratrochlear and supraorbital artery, respectively. METHODS: A total of 50 patients (11 males and 39 females; mean age, 49.76 [13.8] years, mean body mass index, 22.53 [2.6] kg/m2) were investigated with ultrasound imaging. The total thickness and the distance of the arteries from the skin and bone surface were measured with an 18-MHz broadband compact linear array transducer. RESULTS: The deep branch of the supraorbital artery changed plane from deep to superficial to the frontalis muscle at a mean distance of 13 mm (range, 7.0-19.0 mm) in males and at 14 mm (range, 4.0-24.0 mm) in females and for the deep branch of the supratrochlear artery at a mean distance of 14 mm in males and females (range, 10.0-19.0 in males, 4.0-27.0 in females) when measured from the superior orbital rim. CONCLUSIONS: Based on the ultrasound findings in this study, it seems that the supraperiosteal plane of the upper and lower forehead could be targeted during soft tissue filler injections because the deep branches of both the supraorbital and supratrochlear arteries do not travel within this plane. The superficial plane of the lower forehead, however, should be avoided due to the unpredictability and inconsistent presence of the central and paracentral arteries.

Subject and partner satisfaction with lip and perioral enhancement using flexible hyaluronic acid fillers.

BACKGROUND: The injection of hyaluronic acid (HA) dermal fillers is a popular minimally invasive approach to improve lip volume and contour, and with improved techniques has gained popularity because full lips are often associated with beauty and youth. Patient satisfaction is a key driver for successful aesthetic procedures, influencing individual treatment plans and future recommendations. OBJECTIVE: To evaluate subject and partner satisfaction with the hyaluronic acid (HA) dermal filler HARK for lip enhancement at 8 weeks after the last treatment. METHODS & MATERIALS: Subjects in this open-label study all received HARK in the lips, and an additional group also received HARR and/or HARD in nasolabial folds (NLFs) and marionette lines (MLs). Satisfaction was assessed at Weeks 4 and 8 after the last treatment using questionnaires (FACE-Q™ [subjects] and KISSABILITY [subjects and partners]). RESULTS: Nineteen subjects received HARK only; 40 also received HARR and/or HARD . Subjects reported a high level of satisfaction with their lips following treatment. Increases from baseline in the mean total satisfaction score were statistically significant at Weeks 4 and 8 (P ≤ .001). Most subjects (≥89%) reported satisfaction on all FACE-Q questions at Week 8. Both subjects and partners were satisfied with the kissability, appearance, and natural look and feel of the post-treatment results. CONCLUSION: This study demonstrated that HARK resulted in lip enhancement with high levels of subject and partner satisfaction, when used alone or in combination with HARR / HARD in NLFs and MLs.

An Objective, Quantitative Assessment of Flexible Hyaluronic Acid Fillers in Lip and Perioral Enhancement.

BACKGROUND: HARK is an FDA-approved flexible filler designed for lips. OBJECTIVE: To quantitatively evaluate subject outcomes by measuring the change in lip texture, color (redness), lip fullness, and lip and perioral surface stretch (dynamic strain) after treatment. METHODS AND MATERIALS: In this 8-week open-label, Phase IV multicenter study, subjects were treated with HARK in the lips and HARR and/or HARD in perioral wrinkles and folds as add-on treatment. Assessments included 2D photographic analyses of lip texture and color, and 3D photographic assessments of lip enhancement and dynamic strain. RESULTS: HARK significantly improved lip texture (p ≤ .002), lip redness (p < .001), and added fullness to the lips (lip enhancement measurements; p < .001), at Week 8 after treatment. In addition, lower lip wrinkles were significantly reduced (p = .007) and there was a reduction in upper lip wrinkles (not statistically significant). Surface stretch (dynamic strain) in the lip and perioral region was significantly increased after treatment (p < .001). CONCLUSION: This analysis provides an objective measure of the beneficial effects of flexible hyaluronic acid fillers in lip augmentation and perioral enhancement and demonstrates a significantly improved lip texture, red color, and fullness. A significant increase in surface stretch (dynamic strain) is indicative of tissue expansion and improvement in lip smoothness.

Anatomy of the Superior and Inferior Labial Arteries Revised: An Ultrasound Investigation and Implication for Lip Volumization.

BACKGROUND: Lips are considered a key element of facial attractiveness due to their central position in the face and their elemental role in verbal and nonverbal communication. OBJECTIVES: The authors sought to provide clinically relevant information on the 3-dimensional pathway of the superior and inferior labial arteries within the lips to increase safety during labial soft tissue filler injections. METHODS: The study enrolled 41 healthy volunteers with a mean age of 26.17 ±â€…9.6 years and a mean body mass index of 23.09 ±â€…2.3 kg/m2. Ultrasound imaging was performed at 6 different locations. The position of the labial arteries within the lips, depth of the arteries, cranio-caudal location of each artery in relation to the vermilion border, and diameter of the superior/inferior labial arteries were recorded. RESULTS: The most frequent location of both the superior and inferior labial arteries was the submucosal plane (58.5%) followed by intramuscular (36.2%) and subcutaneous (5.3%) planes. The depth of the superior labial artery in the upper lip was 5.6 ±â€…0.13 mm, whereas the depth of the inferior labial artery in the lower lip was 5.2 ±â€…0.14 mm. Both arteries were more frequently located within the red lip: upper lip (83% vs 18.7%) and lower lip (86.2% vs 13.8%). In the midline, the artery coursed within the red lip in all investigated volunteers. CONCLUSIONS: Clinically, results of this study favor a superficial injection plane for lip volumization procedures. A perpendicular approach to the lip (coming from the cutaneous lip) might increase safety because the artery is located most frequently within the red lip.

Relationship Between Vertical Glabellar Lines and the Supratrochlear and Supraorbital Arteries.

BACKGROUND: Glabellar soft tissue filler injections have been shown to be associated with a high risk of causing injection-related visual compromise. OBJECTIVES: The aim of this study was to identify the course of the superficial branch of the supratrochlear and of the deep branch of the supraorbital artery in relation to the ipsilateral vertical glabellar line and to test whether an artery is located deep to this line. METHODS: Forty-one healthy volunteers with a mean age of 26.17 [9.6] years and a mean BMI of 23.09 [2.3] kg/m2 were analyzed. Ultrasound imaging was applied to measure the diameters, distance from skin surface, distance between the midline, distance between vertical glabella lines, and the cutaneous projection of the supratrochlear/supraorbital arteries at rest and upon frowning. RESULTS: The mean distance between the superficial branch of the supratrochlear artery and the ipsilateral vertical glabellar line was 10.59 [4.0] mm in males and 8.21 [4.0] mm in females, whereas it was 22.38 [5.5] mm for the supraorbital artery in males and 20.73 [5.6] mm in females. Upon frowning, a medial shift in supratrochlear arterial position of 1.63 mm in males and 1.84 mm in females and of 3.9 mm in supraorbital arterial position for both genders was observed. The mean depth of the supratrochlear artery was 3.34 [0.6] mm at rest, whereas the depth of the supraorbital artery was 3.54 [0.8] mm. CONCLUSIONS: The hypothesis that injecting soft tissue fillers next to the vertical glabellar line is safe because the supratrochlear artery courses deep to the crease should be rejected. Additionally, the glabella and the supraorbital region should be considered as an area of mobile, rather than static, soft tissues.

An Objective, Quantitative, Dynamic Assessment of Hyaluronic Acid Fillers That Adapt to Facial Movement.

BACKGROUND: Objective dynamic assessments are central to the evaluation of facial rejuvenation treatments. This study used three-dimensional digital stereophotogrammetry to generate a quantitative dynamic assessment of facial strain and hyaluronic acid filler efficacy. METHODS: Thirty women (aged 41 to 65 years) with moderate to severe bilateral nasolabial folds and marionette lines received Restylane Refyne, Restylane Defyne, or both, and were compared to a "younger" untreated group (n = 20; aged 25 to 35 years). Three-dimensional videos were collected at baseline and at day 42. Dynamic strain was analyzed at the marionette lines and nasolabial folds as subjects went from a neutral position through a series of facial expressions. RESULTS: Baseline nasolabial folds and marionette lines showed statistically significant (p ≤ 0.05) differences in the level of stretch between younger and older untreated subjects, with higher stretch profiles observed in the older cohort. In the older cohort, filler treatment reduced peak strain (stretch) in the nasolabial folds and marionette lines compared with baseline across all tested expressions, resembling the youthful strain profile of the younger untreated control group. Treatment was well tolerated. CONCLUSIONS: Quantitative dynamic strain analysis is an innovative method for evaluating the dynamic face following dermal fillers and provides objective evidence that such treatment results in stretch levels resembling a younger phenotype in areas prone to the effects of facial aging. The strain reduction following filler treatment objectively conveys a dermal tightening effect, likely secondary to the volumization of treated areas. Additional studies will refine the technology and associated procedures to optimize quantitative dynamic strain analysis for treatment planning and patient outcome optimization. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.