Reticulated livedoid skin patterns after soft-tissue filler-related vascular adverse events.

BACKGROUND: For the treatment of vascular adverse events caused by filler injections, duplex ultrasound imaging may be used. The findings of duplex ultrasound examination and the clinical features of reticulated livedoid skin patterns were compared with the hemifaces anatomy. OBJECTIVE: The objective of this study was to link the reticulated livedoid skin patterns to the corresponding duplex ultrasound findings and the facial perforasomes. METHODS: Duplex ultrasound imaging was used for the diagnosis and treatment of vascular adverse events. The clinical features and duplex ultrasound findings of 125 patients were investigated. Six cadaver hemifaces were examined to compare the typical livedo skin patterns with the vasculature of the face. RESULTS: Clinically, the affected skin showed a similar reticulated pattern in each facial area corresponding with arterial anatomy and their perforators in the cadaver hemifaces. With duplex ultrasound, a disturbed microvascularization in the superficial fatty layer was visualized. After hyaluronidase injection, clinical improvement of the skin pattern was seen. Normalization of blood flow was noted accompanied by restoration of flow in the corresponding perforator artery. The skin patterns could be linked to the perforators of the superficial fat compartments. CONCLUSION: The livedo skin patterns seen in vascular adverse events may reflect the involvement of the perforators.

Post-Treatment Displacement of Facial Soft Tissue Fillers-A Retrospective Ultrasound-based Investigation of 382 Zygomatic Regions.

BACKGROUND: Clinical and ultrasound experience has revealed that after soft tissue injections of the lateral cheek, the filler may displace from the zygoma to the caudal temporal area. OBJECTIVE: To obtain more data to provide insight into product distribution when soft tissue fillers are injected in the zygomatic region. METHODS: Two hundred patients were examined with facial ultrasound imaging of the zygomatic and temporal region. Inclusion criteria were simply a positive response on the screening questionnaire as to whether or not they had filler injections placed in their lateral cheek. Control injections were also performed to the zygomatic regions of a body donor and in 10 patients ultrasound-guided. RESULTS: A correlation was found between the layers in which filler was detected on the zygoma and where it was ultimately found in the temples. Four different redistribution patterns were observed: (1) migration of filler within the superficial muscular aponeurotic system (SMAS) on the zygoma into the superficial temporal fascia. Migration of filler from the lateral suborbicularis oculi fat to (2) the deep interfacial plane of the temple or (3) to the superficial temporal fat pad; (4) migration from the supraperiosteal layer of the zygoma to the superficial temporal fat pad. Body donor and patients: filler deposits injected on the zygoma were witnessed to shift during injection into the caudal part of the temple. CONCLUSION: Soft tissue filler aliquots may be redistributed into the temples after injections of the lateral side of the zygomatic arch. The displacement follows a distinct pattern depending on the initial layer of injection.

Investigating Facial Muscle Physiology Following Soft Tissue Filler Injections - A surface-derived Electromyographic and Skin Vector Displacement Analytic Study.

The use of hyaluronic - acid based soft - tissue fillers has often been reported to modulate the muscle i.e., to cause myomodulation. To our knowledge, there has been so far no scientific study investigating the potential of hyaluronic - acid based soft - tissue fillers to modulate or actually alter the function of facial muscles. To further assess this 3 - dimensional (3D) surface imaging and electromyography (EMG) based prospective study investigated the changes of facial muscle contraction after injection of strategically placed hyaluronic - acid based soft - tissue fillers to assess the actual validity of the term myomodulation. A total of 13 subjects with a mean age of 37.8 years (12 females, 1 male) were injected according to a predefined injection protocol. Surface electromyography and 3D surface imaging were performed prior to the injection and 5 days after the injection. The results showed no significant change in the strength of the muscles (measured in µV) after injection of hyaluronic - acid based soft - tissue fillers. However, horizontal and vertical skin displacement upon contraction of the zygomaticus major muscle changed significantly between baseline and follow - up , with a mean horizontal skin displacement increase from 3.2 mm to 4.1 mm. Upon contraction of the depressor anguli oris muscle, the horizontal skin displacement did not change significantly (2.15 mm vs. 2.05 mm), while vertical skin displacement increased significantly from 2.9 mm to 4.3 mm. The modification of the surrounding tissue caused an alteration of the vectorial skin displacement upon contraction of the muscle. A potential explanation could be the increased distance between origin and insertion of the muscle due to the material deposition in the proximity of the relevant facial muscles, leading to a change of contraction vector.

The Influence of Scar Patterns After Reduction Mammoplasty on Eye Movement and Gaze Pattern: An Eye-Tracking Investigation.

BACKGROUND: Given that scars are acknowledged as the primary cause of postoperative dissatisfaction following reduction mammoplasty, it is imperative to comprehend the patient's visual perception of different scar patterns in order to enhance patient satisfaction. To achieve this, eye-tracking technology provides an unbiased method of evaluating how observers assess breast scars. METHODS: 58 participants (32 females and 26 males) between the ages of 19 and 82 years (mean age of 29.47 ± 10.98 years) were shown 18 color photographs, taken at 3 viewing angles (right 45° oblique, frontal and frontal view with arms raised), from 6 patients undergone reduction mammoplasty with the inverted T-scar technique (3 patients) or no-vertical-scar technique (3 patients). The images were presented to every participant for a fixed duration of 5 s each. Eye-tracking device was used to collect and analyze the gaze data of viewers. RESULTS: The nipple-areola complex (NAC) and the periareolar scar captured observers' gaze faster, had longer duration and more count of eye fixation than all other parts of breast scars, regardless of the viewing angle and scar pattern. Moreover, the scar region in the inverted T-scar pattern received greater and faster visual attraction of observer's gaze than the no-vertical-scar pattern. CONCLUSION: The NAC and the periareolar scar seem to be perceived as the most important regions for breast aesthetics. The findings can be helpful to assist plastic surgeons in determining the most appropriate technique for reduction mammoplasty, meanwhile underlining the importance of a fine periareolar scar and symmetric NAC for excellent aesthetic outcomes. This is to our best knowledge the first study using eye-tracking technology in evaluating reduction mammoplasty outcomes. This study explored the influence of different scar patterns after reduction mammoplasty on eye movements and gaze patterns among observers. The study have validated the significance of the NAC and the periareolar scar for breast aesthetics and revealed that the scar region in the inverted T-scar pattern may be judged less visually attractive than the no-vertical-scar pattern. 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 .

Investigating the Contraction Pattern of the Zygomaticus Major Muscle and its Clinical Relevance: A Functional MRI Study.

BACKGROUND: Our understanding of facial anatomy has significantly evolved, yet the detailed contraction patterns of facial muscles and their presentation during clinical imaging remain largely unexplored. Understanding the contraction patterns and visual presentation of these muscles, particularly the zygomaticus major could enhance pre-surgical facial assessments and the development of new treatment strategies. METHODS: A total of 34 healthy young individuals (17 female, 17 male) with a mean age of 23.6 (2.4) years [range: 20-30] were investigated regarding the length, thickness, width, and angle of the zygomaticus major muscle in five different facial expressions (i.e., repose, anger, joy, surprise, and sadness) utilizing MR imaging. RESULTS: Joyful expressions caused a reduction in muscle length to 85.6% of its original length and an increase in width (103.4%), thickness (108.4%), and facial angle (2.72°) when compared to that in repose, suggesting isotonic contraction. Conversely, expressions of anger, surprise, and sadness generally led to muscle stretching, seen through changes in length (98.9%, 104.3%, and 102.7%, respectively), width (98.8%, 96.5%, and 99.4%, respectively), and thickness (91.2%, 91.0%, and 102.7%, respectively), with variable alterations in facial angle (0.55°, 1.85°, and 1.00°, respectively) depending on the specific expression. CONCLUSION: This MRI-based study indicates that the zygomaticus major muscle experiences isotonic contraction, characterized by decreased length and increased width and thickness. The findings underline the importance of muscle thickness as a reliable parameter in assessing facial muscle function and offer valuable guidance for practitioners in accurately evaluating muscle performance during different facial expressions. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

Understanding the Interplay Between Skin, Fascia, and Muscles of the Midface in Facial Aging.

BACKGROUND: Surgical, minimally-invasive, and non-invasive aesthetic procedures try to ameliorate the signs of facial aging, but also focus on enhancing various individual features of beauty in each patient. Herein, the midface plays a central role due to its location but also its importance for the aesthetic perception and facial expression. OBJECTIVE: To date, no study has investigated the interplay between facial muscles and its connecting subdermal architecture during facial aging to provide a more comprehensive understanding of the middle face. MATERIALS AND METHODS: A total of 76 subjects, consisting of 30 males (39.5%) and 46 females (60.5%) with a mean age of 42.2 (18.7) years [range 19-80] and a mean BMI of 24.6 (3.7) kg/m2 [range 18-35], were enrolled in this investigation. Cutometry (skin aging), 3D skin displacement analyses (subdermal connective tissue aging), and sEMG (muscle aging) analyses were utilized. RESULTS: The results revealed that overall skin firmness increased, and skin elasticity decreased (p < 0.001), sEMG signal of the investigated muscles decreased (p < 0.001), whereas midfacial mobility remained unaltered (p = 0.722). CONCLUSION: The results of this study indicate that midfacial aging is a measurable effect when utilizing individual measurement modalities for assessing skin, subdermal fascia, and midfacial muscles. The function of midfacial muscles revealed a potential threshold effect, which is not reached during midfacial aging due to the unchanged soft tissue mobility at older age. However, to understand its clinical presentation all midfacial soft tissues need to be factored in and a holistic picture needs to be created. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes review articles, book reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

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.

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.

Increasing Precision When Targeting the Depressor Anguli Oris (DAO) Muscle With Neuromodulators - An Ultrasound-Based Investigation.

BACKGROUND: Neuromodulator treatments of the perioral region are increasingly popular and aim to modulate the position of the modiolus. The predominantly targeted muscle is the depressor anguli oris (DAO) which allows for the modiolus to reposition cranially once temporarily relaxed. OBJECTIVES: To identify the precise anatomic position of the DAO in relation to the Marionette Line for increasing precision and reducing adverse events during neuromodulator treatments. METHODS: A total of n = 80 DAO muscles were investigated in n = 40 healthy, toxin naïve volunteers (11 males, 29 females) having a mean age of 48.15 (15) years and a mean body mass index of 24.07 (3.7) kg/m2. The location of the DAO in relation to the labiomandibular sulcus (LMS), its depth, extent, and thickness were investigated with high frequency ultrasound imaging. RESULTS: The skin surface projection of the LMS separates the DAO into medial and lateral portions. The distance between skin surface and muscle surface was on average 4.4 mm with males having a greater distance (p < 0.001) and higher BMI being an important influencing factor for a greater distance (p < 0.001). The thickness of the DAO was on average 3.5 mm with a range of 2.8-4.8 mm and with females having thinner muscles when compared to men (p < 0.001). The most favorable injection depth was calculated to be 6.1 mm for intra-muscular product placement. CONCLUSIONS: Understanding the perioral anatomy and the influence of age, sex, and BMI will potentially allow the injectors to increase efficacy and duration of neuromodulator treatments while expertly managing adverse events.

Investigating the Anatomic Location of Soft Tissue Fillers in Noninflammatory Nodule Formation: An Ultrasound-Imaging-Based Analysis.

INTRODUCTION: Noninflammatory nodules may be persistent to dissolve. To evaluate the possible reasons, a case series of ultrasound images and medical data of patients who were prospectively referred with noninflammatory nodules were evaluated. MATERIALS AND METHODS: A total of 27 patients with nodules but without signs of inflammation were included. All cases were assessed with an 18-MHz linear ultrasound device. Exact location of the filler material was noted. Relations with clinical data were analyzed using chi-square tests. RESULTS: Early onset of complaints (<2 weeks) was found in 16 patients and late onset (>2 weeks) in 11. All patients had multiple nodules. In all cases, the filler nodule was found to be located inside the fascia. Extension to the subcutaneous tissue was seen in 8 cases and to the deeper planes in 5. In 14 cases, the filler material was completely located inside layers of the fascia, and migration was observed in 5 cases. DISCUSSION: Accumulation of filler material in the superficial musculoaponeurotic system or fascia may be an important cause for the occurrence of persistent noninflammatory nodules, either by initial faulty injection technique or by later accumulation through the pathway generated with a needle or cannula. Ultrasound-guided injections are helpful to dissolve the nodule.

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.

One-Year Data on the Longevity and Safety of Hyaluronic Acid Filler for Static Horizontal Neck Rhytids.

BACKGROUND: The long-term efficacy and safety of hyaluronic acid fillers injected into the neck have yet to be analyzed in a prospective trial in the United States. OBJECTIVE: Analyze the long-term efficacy and safety of a hyaluronic acid filler for static horizontal neck rhytids. MATERIALS AND METHODS: Twenty-six subjects were enrolled in the study. Six subjects were randomized to receive saline and 20 subjects were randomized to receive HA RR. All subjects were randomized to use a cannula on 1 side and needle on the other with optional retreatment on day 30 and optional crossover treatment with different assignment on day 60. The subjects were graded using the Transverse Neck Line Scale, Canfield photography, and the Global Aesthetic Improvement Scale on day 360. RESULTS: A significant improvement from baseline on day 360 was achieved on the Transverse Neck Line Scale according to the blind evaluator, subjects, and investigator without any delayed-onset or prolonged side effects. There was no significant difference in the average improvement from the short-term analysis on day 60 to the long-term analysis on day 360. CONCLUSION: HA RR achieved significant long-term improvement in static horizontal neck rhytids without any long-term side effects.

The perception of lip aesthetics in the context of facial proportions-An eye-tracking-based analysis.

BACKGROUND: Minimally invasive lip volumizing and contouring soft tissue filler procedures are frequently requested by both female and male aesthetic patients. Guidance on how to achieve the most beautiful outcome is inconsistent. OBJECTIVE: To investigate what the most beautiful proportions are in relation to vermillion thickness, the distance of the upper and lower lip in relation to nose and chin, and relation to the bigonial distance. METHODS: This study included a total of n = 101 volunteers (52 females, 49 males, 100% Caucasian) who inspected frontal images of modified facial proportions and answered a related questionnaire showcasing the same images. Image presentation followed a randomized sequence both for the eye tracking and for the survey component of this study but was equal for all observers. RESULTS: The most attractive vertical position of lips was the 1:2 ratio in which the distance between lips and chin is double the length as the distance between lips and nose. For the ratio between the width of the lips and the bigonial distance, it was the 1:2.5 ratio, whereas for the thickness of the upper lip vermilion in relation to the upper lip ergotrid it was the 1:3/1:2 (male/female) ratio and for the lower lip vermilion and lower lip ergotrid it was the 1:4 ratio for both genders. CONCLUSION: The results of this eye tracking and survey-based investigation revealed that instead of one single universal ratio, multiple facial proportions exist that are perceived as most attractive/masculine/feminine. Regarding the perception of facial aesthetics, it appears there is a distinction between attractiveness and masculinity/femininity: the most attractive male/female face is not necessarily the most masculine or feminine.

ChatGPT's quiz skills in different otolaryngology subspecialties: an analysis of 2576 single-choice and multiple-choice board certification preparation questions.

PURPOSE: With the increasing adoption of artificial intelligence (AI) in various domains, including healthcare, there is growing acceptance and interest in consulting AI models to provide medical information and advice. This study aimed to evaluate the accuracy of ChatGPT's responses to practice quiz questions designed for otolaryngology board certification and decipher potential performance disparities across different otolaryngology subspecialties. METHODS: A dataset covering 15 otolaryngology subspecialties was collected from an online learning platform funded by the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery, designed for board certification examination preparation. These questions were entered into ChatGPT, with its responses being analyzed for accuracy and variance in performance. RESULTS: The dataset included 2576 questions (479 multiple-choice and 2097 single-choice), of which 57% (n = 1475) were answered correctly by ChatGPT. An in-depth analysis of question style revealed that single-choice questions were associated with a significantly higher rate (p < 0.001) of correct responses (n = 1313; 63%) compared to multiple-choice questions (n = 162; 34%). Stratified by question categories, ChatGPT yielded the highest rate of correct responses (n = 151; 72%) in the field of allergology, whereas 7 out of 10 questions (n = 65; 71%) on legal otolaryngology aspects were answered incorrectly. CONCLUSION: The study reveals ChatGPT's potential as a supplementary tool for otolaryngology board certification preparation. However, its propensity for errors in certain otolaryngology areas calls for further refinement. Future research should address these limitations to improve ChatGPT's educational use. An approach, with expert collaboration, is recommended for the reliable and accurate integration of such AI models.

Facial Anthropometric Measurements and Principles - Overview and Implications for Aesthetic Treatments.

Facial anatomy is highly individual in each patient. Anthropometric measurements can be a useful tool to objectively analyze individual facial anatomy to allow for better comparability before and after treatments to ultimately improve standardization of facial procedures, both nonsurgical and surgical. The aim of this study was to provide a comprehensive overview over clinically relevant and feasible facial anthropometric measurements and principles for aesthetic medicine. A literature review was conducted to describe the most important and clinically relevant anthropometric measurements and principles for both the entire face and for three aesthetically relevant facial regions: the periorbital region, the nose, and the perioral region. A multitude of different anthropometric measurements and principles have been described in the literature for both the overall facial appearance and specific facial regions. Certain generally accepted anthropometric principles and proportions need to be respected to achieve aesthetic and harmonious results. For the overall facial appearance, a focus on symmetry, certain proportions, facial angles, and indices has been described. Principles and measurements were also described for the periorbital region, the nose, and the perioral region. Although attractiveness and aesthetic perception are subjective, objective evaluation of facial surface anatomy via anthropometric measurements can improve pre- and postinterventional analysis of the face and help the treating physician to individualize treatments, both nonsurgical and surgical.

Arterial Embolism After Facial Fat Grafting: A Systematic Literature Review.

BACKGROUND: While autologous fat grafting of the face is considered a generally safe procedure, severe complications such as arterial embolism (AE) have been reported. OBJECTIVE: To summarize data on injection-related visual compromise, stroke, and death caused by arterial embolism after facial fat transplantation. MATERIALS AND METHODS: Plastic surgery societies were contacted for reports on AE after autologous facial fat injection. In addition, a systematic literature review was performed. Data extracted included study design, injection site/technique, symptoms, management, outcome, and etiology. RESULTS: 61 patients with a mean age of 33.56 ± 11.45 years were reported. Injections targeted the glabella or multiple facial regions (both n = 16/61, 26.2%) most commonly, followed by injections in the temples (n = 10/61, 16.4%) and the forehead (n = 9/61, 14.8%). The mean volume injected was 21.5 ± 21.5 ml. Visual symptoms were described most frequently (n = 24/58, 41.4%) followed by neurological symptoms (n = 20/58, 34.5%), or both (n = 13/58, 22.4%). Ophthalmic artery (OA, n = 26/60, 43.3%), anterior or middle cerebral artery (CA, n = 11/60, 18.3%) or both (n = 14/60, 23.3%) were most frequently occluded. Outcome analysis revealed permanent vision loss in all patients with OA occlusion (n = 26/26, 100%), neurological impairment in most patients with CA occlusion (n = 8/10, 80%), and vision loss in most patients suffering from both OA and CA occlusion (n = 7/11, 63.6%). Six patients died following embolisms. CONCLUSIONS: AE causes severe complications such as blindness, stroke, and death. Due to a lack of high-quality data, no evidence-based treatment algorithms exist. To increase patient safety, a database collecting cases and complications should be established. LEVEL OF EVIDENCE III: 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 .

Multimodal Analyses of the Aging Forehead and Their Clinical Implications.

BACKGROUND: Recent research has indicated that in the upper face a delicate arrangement exists between the muscles of facial expression and the skin. This arrangement allows for immediate transmission of movements following muscle contraction, resulting in skin movements and skin rhytid formation. OBJECTIVES: To investigate age-related changes of the biomechanical unit formed by facial muscles, their connective tissue envelope, and the skin of the upper face. METHODS: A total of 76 Caucasian volunteers (30 males, 46 females) with a mean age of 42.2 years (SD 18.6) and a mean body mass index of 24.58 kg/m2 (SD 3.7) were investigated. Three upper facial regions were analyzed for skin firmness and elasticity with cutometric assessment, vertical and horizontal skin vector displacement using 3-dimensional imaging, and muscle activity with surface-derived electromyography. RESULTS: Study participants of older age (>42.2 years), when compared with younger participants (≤42.2 years), showed increased skin firmness, at 0.20 mm vs 0.30 mm (P < .001); decreased skin elasticity at 53.2% vs 69.0% (P < .001); increased vertical (not horizontal) skin mobility at 3.56 mm vs 1.35 mm (P < .001); and decreased surface-derived electromyography (sEMG) signal of the frontalis muscle with 174 µV vs 309 µV (P = .039). CONCLUSIONS: This study reveals that age-related changes occur in each component of the biomechanical unit formed by facial muscles, connective tissue envelope, and skin in the upper face. Knowledge and understanding of such changes can allow for more targeted and individualized surgical and nonsurgical aesthetic treatments.

Ex Vivo Product Distribution of Injectable Biostimulator Substances.

BACKGROUND: Increasing demand for minimally invasive aesthetic treatments, such as injection of biostimulator substances to induce the production of extracellular matrix, has been reported. Recent studies have reported on a variety of different product characteristics influencing the integration and distribution of biostimulator substances after injection. OBJECTIVES: The aim of this study was to analyze the ex vivo product integration and distribution behavior of 6 different biostimulator substances after injection. METHODS: A total of n = 21 abdominal soft tissue flaps were analysed by real-time ultrasound imaging with regards to horizontal and vertical spread of 6 different injected biostimulator substances-based on hydroxylapatite (HA), polycaprolactone (PCL), and poly-L-lactic acid (PLLA)-immediately after injection and after massaging. The 6 different biostimulator substances were R-CaHA-based, H-CaHA-based, PCL-based, PLLA-1-based, PLLA-2-based and H-HA-based products. RESULTS: Overall, the R-CaHA-, H-CaHA-, and PCL-based substances showed greater product spread after massaging when compared with the product distribution immediately after the injection with all P < .001 with the exception of the vertical dimension of the H-CaHA-based substance (P = .064). The PLLA-1-, PLLA-2-, and H-HA-based substances showed smaller product spread after massaging compared with the product distribution immediately after the injection with all P < .001 with the exception of the horizontal dimension of the H-HA-based substance (P = .314), indicating higher tissue integration. CONCLUSIONS: Different biostimulator substances behave differently when injected into subcutaneous soft tissues; differences exist at the level of initial product diffusion and during tissue integration.

Ultrasound-Guided Targeted vs Regional Flooding: A Comparative Study for Improving the Clinical Outcome in Soft Tissue Filler Vascular Adverse Event Management.

BACKGROUND: Adverse vascular event management following hyaluronic acid-based aesthetic injections relies on the administration of hyaluronidase which is capable of enzymatically degrading the injected product and improving clinical symptoms. Two protocols are currently available to manage such complications: "ultrasound-guided targeted" and "flooding". OBJECTIVES: The aim of this study was to compare the 2 protocols in terms of the volume of hyaluronidase utilized, and the onset and degree of clinical improvement. METHODS: A comparative case series of 39 patients was retrospectively evaluated. The patients were initially treated with the "flooding" protocol and then treated with the "ultrasound-guided targeted" protocol due to no or little improvement. RESULTS: The "ultrasound-guided targeted" protocol utilized a mean [standard deviation] total of 122.5 [34] IU of hyaluronidase, whereas the "flooding" protocol utilized 1519.4 [1137] IU, which represents a statistically significant reduced amount of injected hyaluronidase (P = 0.028). There was no clinical improvement in 92.3% and only little improvement in 7.7% of the treated patients following the first applied "flooding" protocol, but there was a 100% immediate improvement when subsequently treated with the "ultrasound-guided targeted" protocol. Ultrasound imaging revealed that the application of hyaluronidase restored normal blood flow both in the perivascular space and in the superficially located subdermal soft tissues. CONCLUSIONS: Despite its limitations in study design, this retrospectively evaluated case series revealed that the "ultrasound-guided targeted" protocol utilized less hyaluronidase and restored clinically visible symptoms faster. The effect of this protocol is best explained by the perforasome concept which will need to be investigated further in future studies.

Precision of Soft-Tissue Filler Injections: An Ultrasound-Based Verification Study.

BACKGROUND: Uncontrolled product spread is an important issue to consider in facial filler injections. Lack of precision can result in reduced effectiveness and surface projection, as well as irregularities and product visibility. OBJECTIVES: The authors sought to assess the precision of soft-tissue filler injections in the face by employing a cannula. METHODS: This single-center observational study investigated soft-tissue filler distribution utilizing real-time non-invasive ultrasound imaging. Outcome parameters included (1) the tissue plane of product distribution, (2) the extent of horizontal as well as vertical product spread at the injection site, and (3) the product surface area taking into account the multifactorial influence of several independent variables. Participants were followed up to 30 days post-injection. RESULTS: A total 100 facial injections were performed in 8 patients (2 males, 6 females) with a mean age of 37.20 (±6.34) years and a mean BMI of 22.21 (±1.39) kg/m.2. The plane of product distribution remained constant in approximately 90% of cases at day 0 (d0), d14, and d30. Mean horizontal product spread was higher compared with vertical spread, and both significantly decreased over all time points (P < .001). Mean product surface area was 22.51 ± 16.34 mm2 at d0, 15.97 ± 11.28 mm2 at d14, and 12.9 ± 9.15 mm2 at d30. Analysis employing generalized linear models revealed that injection volume and injection depth significantly influenced product surface area. CONCLUSIONS: Injection of soft-tissue filler employing a cannula allows precise application of the product within the intended tissue plane. Precision can be improved by injecting less product into deeper tissue layers.