Effectiveness of hyaluronic acid fillers for cheek augmentation using a treatment guide to choose between products.

BACKGROUND: Patients can have different reasons for seeking cheek augmentation; while some are in need of volume augmentation, others may request projection and lifting. A treatment guide can be useful for treating clinicians in choosing the most suitable product. AIMS: This 8-week, multicenter study was conducted to evaluate the effectiveness and safety of cheek augmentation using a treatment guide to choose between study products HACON and HALYF. PATIENTS/METHODS: Female subjects intending to undergo cheek augmentation were treated according to primary need for treatment-HACON for contouring or HALYF for projection. Treatments were performed according to approved labels. Assessments included Global Aesthetic Improvement Scale (GAIS) evaluations, subject satisfaction, subject-perceived age (FACE-Q), naturalness of facial expressions, 3D imaging analysis, and safety assessments. RESULTS: All subjects (n = 60) were assessed as aesthetically improved by the investigators 4 and 8 weeks after last injection. For all subjects, contouring or projection was achieved as planned with natural-looking results. Subject satisfaction was high in both study groups. Volume change of the cheek area was statistically significant from baseline to Week 4 (p < 0.001), in both treatment groups and on both sides of the face. Overall, treatments were well tolerated with mainly mild adverse events related to treatment. CONCLUSIONS: The proposed guide for product selection of HACON or HALYF for treatment of the cheek area was useful to achieve the primary treatment goal for both products. Treatments were well tolerated and associated with improved aesthetic appearance of the cheeks as well as high subject satisfaction.

Intracorporeal evaluation of hyaluronic acid fillers with varied rheological properties and correlations with aesthetic outcomes.

BACKGROUND: Understanding the differences in soft tissue filler rheology and how these properties can impact clinical results is a fundamental concepts for any injector. This study aimed to assess the tissue integration characteristics of hyaluronic acid (HA) fillers manufactured with different technologies (Non-Animal Stabilized HA [HA-N] or Optimal Balance Technology [HA-O]) using ultra-high-frequency ultrasound. METHODS: Twelve female participants with mild-to-moderate midface volume loss and temporal hollowing were enrolled and treated with HA-N and/or HA-O. Participants were seen at five visits (screening/baseline [treatment], and Weeks 1 [optional touch-up], 4, 6, and 8 [follow-up visits]). Ultrasound was used to evaluate the degree of product integration. RESULTS: On ultrasound, HA-N presented with distinct borders, minimal tissue integration, and a capacity to displace tissues. Conversely, HA-O tended to spread horizontally within the same tissue plane and integrated within tissues. The volumizing capacity of the HA-O fillers was dependent on particle size. CONCLUSION: HA-N is suited for deep injections in areas such as the upper lateral cheek and under the muscle of the temporal region when a lifting effect is desired; HA-O is best suited for subcutaneous injections, in areas of dynamic movement or for patients with thin skin; and can be injected subcutaneously or supraperiosteally when a volumizing effect is desired.

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.

Identifying Levels of Competency in Aesthetic Medicine: A Questionnaire-Based Study.

BACKGROUND: In 2022, the US experienced a significant increase in demand for minimally invasive aesthetic procedures, underscoring its rising acceptance amidst an unregulated educational environment for practitioners. The absence of standardized educational pathways and quality control in aesthetic medicine, primarily provided by non-academic institutions, highlights a critical need for establishing educational standards to ensure practitioner competence and patient safety. OBJECTIVES: To identify levels of competency for the aesthetic practitioner and for necessary achievement milestones during the educational path from novice to expert injector. METHODS: A total of n = 386 international study participants responded to an online questionnaire regarding their experience in aesthetic medicine practice. The questionnaire comprised 58 questions focusing on professional data, the perceived difficulty of injection and risk for the occurrence of adverse events for specific facial regions in soft tissue filler and toxin injections. RESULTS: Regardless of medical specialty and experience level, an average of 3.85 (1.8) years, 786.4 (2,628) filler injections, and 549.9 (1,543) toxin injections was estimated to progress from novice to advanced injector, while an average of 6.10 (3.7) years, 1,842.2 (4,793) filler injections, and 1,308.5 (3,363) injections was estimated to advance from advanced to expert injector. The nose and the perioral region have been ranked as the facial regions most difficult to achieve a perfect aesthetic outcome and with the greatest risk for the occurrence of adverse events for filler and toxin injections, respectively. CONCLUSIONS: This study establishes an educational framework in aesthetic medicine by defining the progression from novice to competent and expert injector levels, suggesting 4 years of practice and over 790 filler and 550 neuromodulator injections for competence, and at least 6 years with 1,840 filler and 1,310 neuromodulator injections for expertise. It also identifies critical facial regions for targeted treatments by different expertise levels.

Simplifying the injector's armamentarium: An international consensus regarding the use of gel science to differentiate hyaluronic acid fillers and guide treatment recommendations.

BACKGROUND: The Restylane portfolio of soft tissue fillers spans a wide range of indications, due in part to their complementary manufacturing technologies [non-animal stabilized hyaluronic acid (NASHA) and Optimal Balance Technology (OBT/XpresHAn)]. Using an array of products, injectors can achieve a holistic, natural looking effect for their patients. However, with a wide range of products it may be difficult to choose an optimal combination. AIM: Simplify and align global use recommendations for NASHA versus OBT products. METHODS: Two pre-meeting surveys were completed by 11 key opinion leaders with international representation, with the goal of collecting information regarding their current injection practices for various anatomical regions of the face (i.e., temporal region, forehead, tear trough, lateral zygoma, anteromedial cheek, nose, pyriform aperture, nasolabial fold, perioral area, lips, labiomental crease, marionette lines, chin, and jawline). The data collected from these surveys was subsequently discussed in a consensus group meeting involving 11 voting members and 3 nonvoting members. RESULTS: Top product recommendations were identified for each anatomical area, along with secondary and tertiary recommendations that can also be used under defined circumstances. Recommendations were provided based on a consideration of elements such as patient features (e.g., skin thickness, bone structure), the desired aesthetic outcome, experience of the injector, and the preferred injection technique. CONCLUSION: A majority consensus regarding the top NASHA versus OBT product choice for each anatomical region of the face was reached. These recommendations represent international agreement regarding the use of Restylane products.

Evaluation of the Hydrophilic, Cohesive, and Physical Properties of Eight Hyaluronic Acid Fillers: Clinical Implications of Gel Differentiation.

Background: Hyaluronic acid (HA) fillers are used to treat an array of aesthetic indications. Proper filler selection is paramount for successful patient outcomes. However, many important physiochemical and physical properties that impact HA gel behavior remain undefined. Purpose: To evaluate the hydrophilicity, cohesivity and particle size of eight commercial HA fillers manufactured by either Non-Animal Stabilized Hyaluronic Acid (NASHA) or Optimal Balance Technology (OBT) techniques. Methods and Materials: Three individual in vitro experiments were performed to assess HA swelling capacity, cohesion, and particle size. Image analyses, blinded evaluation using the Gavard-Sundaram Cohesivity Scale, and laser diffraction technology were utilized, respectively. Results: Compared to fillers manufactured with NASHA technology, OBT products demonstrated greater swelling capacity, cohesion, and wider particle size distributions. Strong positive correlations between swelling factor, degree of cohesivity, and increasing widths of the particle size distributions were observed. Conclusions: The hydrophilicity, cohesivity and particle size distributions vary among HA fillers manufactured with different techniques. The creation of new labels identifying products based on their unique combination of physiochemical and physical characteristics may help guide appropriate selection of HA fillers to optimize patient outcomes.

Understanding Platysma Muscle Contraction Pattern and Its Relationship to Platysmal Banding: A Real-Time Ultrasound Study.

BACKGROUND: Addressing neck contouring with surgical and nonsurgical aesthetic procedures includes understanding the origin of platysmal banding. A theory was postulated to explain this phenomenon by isometric vs isotonic muscular contraction patterns. However, no scientific proof had been provided to date for its correctness. OBJECTIVES: The aim of this study was to confirm the correctness of the platysmal banding theory based on isometric vs isotonic muscular contractions. METHODS: Eighty platysma muscles from 40 volunteers (15 males and 25 females) were investigated (mean age 41.8; SD 15.2 years; mean BMI of 22.2; SD 2.3 kg/m2). Real-time ultrasound imaging was utilized to measure the increase in local muscle thickness inside and outside of a platysmal band as well as platysma mobility. RESULTS: Within a platysmal band, the local thickness of the muscle increases during muscular contractions by 0.33 mm (37.9%; P < .001). Outside of a platysmal band the thickness of the platysma muscle decreased by 0.13 mm (20.3%; P < .001). It was identified that within a platysmal band no gliding was detectable, whereas outside of a band an average muscle gliding of 2.76 mm was observed. CONCLUSIONS: The results confirm the correctness of the isometric vs isotonic platysma muscle contraction pattern theory: isotonic muscle contraction (gliding without increase in tension and therefore in muscle thickness) vs isometric muscle contraction (no gliding but increase in tension and therefore in muscle thickness). These 2 types of contraction patterns occur within the platysma simultaneously and are an indicator for zones of adhesion in the neck to guide surgical and nonsurgical aesthetic procedures.

Is constant needle motion during soft tissue filler injections a safer procedure? A theoretical mathematical model for evaluating patient safety.

BACKGROUND: The safety rationale behind the constant needle motion injection technique is based on the assumption that due to the constant needle motion and simultaneous soft tissue filler material administration a smaller amount of product per area may be injected into an artery if an artery within the range of the moving needle is inadvertently entered. OBJECTIVE: To perform mathematical calculations for determining the probability for causing intra-arterial product administration when constantly moving the needle during facial aesthetic soft tissue filler injections. METHODS: This study was designed as a theoretical investigation into the probabilities for causing adverse events due to intravascular injection of soft tissue filler material when constantly moving a 27-G needle during facial soft tissue filler administration. RESULTS: It was revealed that with a higher number of conducted injection passes a greater soft tissue area can be covered by the needle. The odds of encountering an artery within the covered soft tissue volume and the odds of injecting any volume greater than zero into the arterial blood stream increases with the number of performed injection passes. This increase is greatest between 1 and 10 performed injection passes. CONCLUSION: This model demonstrates that the constant needle motion technique increases the probability of encountering an artery within the treatment area and thus increases the odds for intra-arterial product administration. The constant needle motion technique does not increase safety but rather may increase the odds of causing intra-arterial product administration with the respective adverse consequences for the patient.

The Suitability of a Large Particle Hyaluronic Acid Filler for the Treatment of Temporal Hollowing.

BACKGROUND: Hyaluronic acid (HA) fillers may be manufactured to have distinctive physical properties that optimize their use for specific indications. Fillers manufactured with large gel calibration (particle size; HA-V) may be particularly suitable for volumizing large surface areas such as the temporal hollows. OBJECTIVE: To investigate the safety and effectiveness of HA-V for the treatment of temporal hollows. MATERIALS AND METHODS: A prospective, open-label, single-cohort, clinical trial was conducted. Twenty-six women who presented with bilateral temporal hollows at baseline were recruited. All subjects received treatment with HA-V and were observed at 4 to 5 in-person visits over 16 weeks. Subjective and objective measures of safety and efficacy parameters were collected through 2- and 3-dimensional imagery, questionnaires/scales (i.e., subject satisfaction, global aesthetic improvement, temporal hollowing severity), and adverse event diaries. RESULTS: To achieve optimal correction, the investigator used an average of 1.70 syringes per subject, per side. All treatments were performed using a bolus injection technique to place the product on the periosteum (bone) of the temporal region. Following optimal correction, all subjects (100%) displayed improvement in their global aesthetic appearance, and 25 of 26 subjects (96.15%) displayed ≥1 grade improvement on the temporal volume scale. Subject satisfaction was high, with 91.3% of subjects being satisfied with the appearance of their temporal regions following optimal correction. CONCLUSION: In this pivotal trial, HA-V was evidenced to have an excellent safety profile and proven efficacy up to 16 weeks, making it a suitable HA filler for volumization of the temporal region.

Safety of infraorbital hyaluronic acid injections: Outcomes of a meta-analysis on prospective clinical trials.

BACKGROUND: Hollowing of the infraorbital region represents a common concern among aesthetic patients. In the past decade, an increasing number of patients have resorted to noninvasive aesthetic procedures to treat these concerns. The objective of this study was to evaluate the safety profile of infraorbital hyaluronic acid injections for aesthetic rejuvenation. METHODS: Through a systematic review and meta-analysis of prospective clinical trials, investigators sought to answer the research question "Does the use of needle versus cannula during infraorbital HA injections result in the same incidence rate of adverse events?" The primary outcomes of interest were the incidence rates of ecchymosis and edema in subject groups treated with a needle or cannula. RESULTS: Subjects treated with needles had a statistically significant greater incidence rate of ecchymosis, compared to those treated with cannula. Conversely, subjects treated with cannula had a statistically significant greater incidence rate of edema, compared to those treated with needles. CONCLUSIONS: The incidence rates of adverse events following the administration of hyaluronic acid injections in the infraorbital region vary depending on whether a needle or cannula is used; with needles being associated with a greater risk of ecchymosis and cannulas being associated with a greater risk of edema. These findings should be discussed with patients prior to treatment consultation. Finally, as with most techniques, it is usually prudent to develop expertise with one technique before using a second, especially in cases where both approaches can be used and have different adverse event profiles.

A Computed Tomographic Investigation of the Ophthalmic Artery Volume and Its Relevance to Soft Tissue Filler Injections.

BACKGROUND: The measured intraarterial volume of cadaveric ophthalmic arteries was utilized for safety recommendations during facial soft tissue filler injections. However, its clinical practicability and model applicability have become questionable. OBJECTIVES: To measure the volume of the ophthalmic artery in living individuals by utilizing computed tomography (CT) imaging technology. METHODS: A total of 40 Chinese patients (23 males, 17 females) were included in this study with a mean age of 61.0 (14.2) years and a mean body mass index of 23.7 (3.3) kg/m2. Patients were investigated with CT imaging technology to evaluate the length, diameter, and volume of the bilateral ophthalmic arteries as well as the length of the bony orbits, resulting in a total of 80 investigated ophthalmic arteries and orbits. RESULTS: Independent of gender, the average length of the ophthalmic artery was 80.6 (18.7) mm, the calculated volume of the ophthalmic artery was 0.16 (0.05) mL and the minimal and maximal internal diameter of the ophthalmic artery were 0.50 (0.05) mm and 1.06 (0.1) mm, respectively. CONCLUSIONS: Based on the results obtained from the investigation of 80 ophthalmic arteries it must be concluded that current safety recommendations should be reevaluated. The volume of the ophthalmic artery appears to be 0.2 mL rather than 0.1 mL as previously reported. In addition, it appears impractical to limit the volume of soft tissue filler bolus injections to 0.1 mL due to the aesthetic requirements of each individual patient and treatment plan.

Novel Treatment Protocol for Combined Tear Trough Ligament Stretching and Injection.

BACKGROUND: Complex anatomical changes have been the main challenges for optimal treatment results of tear trough deformities through hyaluronic acid (HA) injections. The authors present a novel technique consisting of a preinjection tear trough ligament stretching (TTLS-I) leading to its release, and compared its efficacy, safety, and patient satisfaction to tear trough deformity injection (TTDI). METHODS: This was a 4-year, retrospective, single-center cohort study of 83 TTLS-I patients, with a follow-up period of 1 year. One hundred thirty-five TTDI patients served as a comparison group. Outcome analyses included the analysis of possible risk factors for adverse outcome and comparative statistics between the complication and satisfaction rates of the two groups. RESULTS: TTLS-I patients received significantly less HA (0.3 cc; range, 0.2 to 0.3 cc) than TTDI patients did (0.6 cc; range, 0.6 to 0.8 cc; P < 0.001). The injected HA amount was a significant predictive factor for complications ( P < 0.05). Complication rates assessed during the follow-up visit for hematomas, edema, and the need for corrective hyaluronidase injection were low in both groups, with no significant differences between the groups. TTDI patients had significantly higher rates (5.1%) of lump surface irregularities during follow-up, compared with 0% in the TTLS-I group ( P < 0.05). After 1 year of follow-up, 98.8% of TTLS-I patients were satisfied, whereas 95.6% of TTDI patients were satisfied, with no significant difference between groups. CONCLUSIONS: TTLS-I is a novel, safe, and effective treatment method, necessitating significantly less HA compared with TTDI. Moreover, it leads to very high satisfaction rates and very low complication rates. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Expert Recommendations on the Use of Hyaluronic Acid Filler for Tear Trough Rejuvenation.

Restylane® Lidocaine is one of the most widely used hyaluronic acid (HA) fillers to replace lost or displaced volume during tear trough correction. Patient goals for tear trough correction include looking less tired or removing dark circles and this may be achieved by administering HA filler into the infraorbital region to correct the lower eyelid relative to the volume deficit, thereby smoothing the transition from the lower eyelid to the cheek. To achieve patient satisfaction and consistent results with Restylane, optimal application is essential; however, clinical guidance based on experience is limited. This paper reflects the recommendations of an interdisciplinary expert panel for the use of Restylane in correcting tear trough deformity, including patient selection, dosing, injection technique, and post-treatment care. Recommendations were discussed and agreed as a consensus, according to cross-sectional expertise and clinical experience. J Drugs Dermatol. 2022;21(4):387-392. doi:10.36849/JDD.6597.

A Prospective, Multicenter Trial on the Efficacy and Safety of Poly-L-Lactic Acid for the Treatment of Contour Deformities of the Buttock Regions.

BACKGROUND: There is a significant emphasis on minimally invasive whole-body rejuvenation throughout the world. Recently, gluteal aesthetics have become an increasingly common patient concern. Although the application of poly-L-lactic acid (PLLA) to the face is already well known, there are relatively fewer publications on its use in other corporeal regions. This study aims to extend previous findings by evaluating the efficacy and safety of PLLA in the treatment of contour (including lifting) deformities of the buttock region. METHODS: This was a prospective, multicenter (3 sites), single cohort, open-label clinical trial. Thirty female subjects were treated with PLLA in the bilateral buttocks, with three treatment sessions, each spaced one month apart and followed for six months after completion of the treatment regimen. At each visit, various safety and clinical efficacy parameters were collected, these included: Global Assessment of Improvement Scale (GAIS), subject satisfaction, skin hydration, elasticity, scaliness, roughness, and 3-dimensional imagery. RESULTS: Six months following the last treatment, 84.00% of patients were rated as having “improved” or more on the physician assessed GAIS, accompanied by a 96.00% patient satisfaction rate. Approximately three vials of PLLA, per buttock and treatment were used. There were no serious adverse events throughout the duration of the trial, nor adverse events related to the investigational device. The most common subject-reported adverse events included pain during treatment (Mean: 70.97%) and bruising (Mean: 28.80%). Objective improvements were persistent after treatment in measurements of skin elasticity (improved 63.5% - 82.5% from weeks 16-32), hydration (increased ~11 Corneometer® units by week 16), roughness (decreased 36.95% at week 32), and scaliness (desquamation; decreased 60.41% at week 32). CONCLUSIONS: PLLA is safe and effective for the indication of buttock contouring and improving parameters of skin health. PLLA can provide long-lasting effects with a high level of patient and physician satisfaction. J Drugs Dermatol. 2022;21(3):304-308. doi:10.36849/JDD.5924.

Tips and Tricks for Facial Toxin Injections with Illustrated Anatomy.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Recognize facial muscle contraction direction and muscle morphology based on skin surface movements and facial rhytides. 2. Classify different muscle contraction patterns and target respectively with the recommended dosage and injection technique. 3. Apply the presented injection techniques to the patients' individual anatomy with greater precision and without affecting adjacent muscles or causing other adverse events. SUMMARY: Facial muscular anatomy has recently gained increased attention, with new investigative methodologies and new injection techniques arising on the market. These recent advancements have increased our understanding about the functional anatomy of facial muscles and have changed the way health care professionals see and understand their interplay during various facial expressions and in determining facial shape. This new anatomical understanding of facial muscles and their interaction has resulted in superior neuromodulator treatment outcomes with fewer side effects and with increased precision. The latter is of greatest importance, as all facial muscles act as a unit and connect with each other. It is therefore paramount to target during neuromodulator treatments only the muscle responsible for the aesthetic effect desired and not other adjacent muscles, which can have different or even antagonistic effects. Conventional anatomy was previously limited to two-dimensional explanations of muscle locations without incorporating their detailed action or their three-dimensional location of extent. The "new" anatomy incorporates those novel concepts and, once understood, will help health care providers to understand better and to "read" the underlying muscular anatomy based on the wrinkle status and based on the change in skin surface landmarks based on the actions of the underlying musculature. The following article summarizes tips and tricks, pearls and pitfalls, and dos and don'ts during facial neuromodulator injections along with a guide toward adverse event management and patient outcome assessment with special focus on the underlying anatomy.

A Randomized, Crossover-Controlled Evaluator-Blinded Trial Evaluating Cannula- vs Needle-Assisted Hyaluronic Acid Injections for Infraorbital Deformities.

BACKGROUND: Periorbital deformities can be corrected utilizing hyaluronic acid injections. However, previous studies have not evaluated the effect of utilizing different injection techniques (eg, a needle vs cannula) on efficacy and safety. OBJECTIVES: The authors sought to investigate the efficacy and safety of HA for the correction of periorbital deformities when utilizing either needle or cannula-assisted injections. METHODS: This was a prospective, randomized-controlled (with crossover), evaluator-blinded study. Forty-two patients with a mean age of 44.82 ± 11.62 years were recruited. Patients underwent 2 treatment sessions, spaced 2 weeks apart, and attended 1 follow-up visit at Week 4, following the last treatment. Patients were randomized in a 3:3:1 ratio, whereby 18 patients received injections by needle, 18 received injections by cannula, and 6 were randomized to act as their own control at baseline. Those in the control group were randomized (n = 3) to needle or cannula injections at Week 4 and proceeded with the same visit schedule as those treated at baseline. At Weeks 2 and 4 posttreatment, patient satisfaction was evaluated and information on adverse effects was collected. A blinded reviewer assessed patient imagery utilizing standardized efficacy scales. RESULTS: Chi-square tests did not reveal any associations between treatment group and efficacy, safety, or patient satisfaction scores (P ≥ 0.05). Adverse effects reported in patient diaries were mild to moderate in nature and expected. CONCLUSIONS: For the treatment of infraorbital deformities, hyaluronic acid injections performed utilizing either a cannula or needle result in similarly high efficacy and safety ratios.

Topography of the deep temporal arteries and implications for performing safe aesthetic injections.

BACKGROUND: Several studies have started investigating the safety of temporal rejuvenation using soft tissue fillers. However, as the temporal region is highly vascularized, adverse events due to intravascular injection are of primary concern. The scarcity of treatment guidelines to date have focused primarily on avoiding the superficial and middle temporal arteries. The aim of the present anatomical study was to describe the topography of the deep temporal arteries (DTAs) with reference to superficial landmarks, to aid clinicians who perform temporal injections. METHODS: The tissue layers of eight fresh-frozen cephalic cadavers were dissected and assessed, bilaterally in the temporal region (N = 16). Distance (D) of the anterior (D1 and D3) and posterior (D2 and D4) arteries was measured from (i) the zygomaticofrontal suture line at the lateral orbital rim (D1 and D2) and (ii) the junction of the superior border of the zygomatic arch and lateral orbital rim (D3 and D4). The distance between the anterior and posterior DTAs was also recorded, at the two regions (D5). RESULTS: Bifurcations of the DTAs were observed in 18.75% (3/16) and 12.5% (2/16) of cases, for the anterior and posterior branches, respectively. On average [mean (standard deviation)], D1 (anterior DTA to the zygomaticofrontal suture line at the lateral orbital rim) = 1.56 cm (0.59); D2 (posterior DTA to the zygomaticofrontal suture line at the lateral orbital rim) = 2.98 cm (0.70); D3 (anterior DTA to the junction of the superior border of the zygomatic arch and lateral orbital rim) = 1.14 cm (0.63); D4 (posterior DTA to the junction of the superior border of the zygomatic arch and lateral orbital rim) = 2.37 cm (0.62); and D5 (distance between the anterior and posterior DTAs) = 1.54 cm (0.68). CONCLUSION: To help avoid vascular adverse events while performing temporal injections, aesthetic clinicians should be conscientious of safety implications related to the anatomical location of the DTAs and their ramifications.

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.

Evaluating safety in hyaluronic acid lip injections.

INTRODUCTION: Soft tissue filler augmentation has become increasingly popular due to its perceived ease and impressive results. Unfortunately, although the results are impressive, so are the reported complications. This article describes complications specific to peri-oral soft tissue filler injection and then discusses evidence-based, anatomic prevention and treatment guidelines. AREAS COVERED: The authors aimed at providing an overview of the complications associated with peri-oral soft tissue filler. Hyaluronic Acid (H.A) fillers may have devastating complications which are oft undisclosed or published. This narrative review aims to describe the various complications and provide preventative strategies. EXPERT OPINION: Given the paucity of prospective, randomized clinical trials on the subject and in light of complication underreporting, the authors believe that efficacy and safety literature on the subject is lacking. Injectors must rely on the one strength which exists in the lip literature to date, that is anatomy. The basis of all successful injections is a mandatory understanding of normal as well as variations of vital structures in an area, combined with meticulous injection techniques, deposition of small aliquots of product and the ability to recognize unwanted adverse events early enough to act on them.